Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. An individual, group, structure, or other entity regarded as an elementary structural or functional constituent of a whole.
  • n. A group regarded as a distinct entity within a larger group.
  • n. A mechanical part or module.
  • n. An entire apparatus or the equipment that performs a specific function.
  • n. A precisely specified quantity in terms of which the magnitudes of other quantities of the same kind can be stated.
  • n. Medicine The quantity of a vaccine, serum, drug, or other agent necessary to produce a specific effect.
  • n. A fixed amount of scholastic study used as a basis for calculating academic credits, usually measured in hours of classroom instruction or laboratory work.
  • n. A section of an academic course focusing on a selected theme: a unit on Native Americans.
  • n. The number immediately to the left of the decimal point in the Arabic numeral system.
  • n. Mathematics The lowest positive whole number; one.
  • n. Mathematics An element of a ring with a multiplicative inverse.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A standard measure of a quantity.
  • n. The number one.
  • n. Short form of international unit
  • n. An organized group comprising people and/or equipment.
  • n. A member of a military organization.
  • n. An element of a ring having a multiplicative inverse. (Formerly just the identity element 1R of a ring.)
  • n. A volume of rock or ice of identifiable origin and age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features (facies) that characterize it.
  • n. An item which may be sold singly.
  • n. One kilowatt-hour (as recorded on an electricity meter).
  • n. a measure of housing equivalent to the living quarters of one household, an apartment where a group of apartments is contained in one or more multi-storied buildings or a group of dwellings is in one or more single storey buildings, usually arranged around a driveway.
  • adj. For each unit.
  • adj. Having a size or magnitude of one.

from the GNU version of the Collaborative International Dictionary of English

  • n. A single thing or person.
  • n. The least whole number; one.
  • n. A gold coin of the reign of James I., of the value of twenty shillings.
  • n. Any determinate amount or quantity (as of length, time, heat, value) adopted as a standard of measurement for other amounts or quantities of the same kind.
  • n. A single thing, as a magnitude or number, regarded as an undivided whole.

from The Century Dictionary and Cyclopedia

  • n. Any subdivision of an army having a distinct organization and defined duties.
  • n. According to the hypothesis of Herbert Spencer, an ultimate biological unit or element which, when joined to others like itself, possesses the power to become a specific organism. The body of each individual organism is held to consist of its own sort of physiological units which are all alike and nearly, but not completely, identical with those which compose the body of another individual of the same species. The physiological unit is held to be intermediate between the molecule or chemical unit and the cell or morphological unit, each cell being regarded as composed of innumerable physiological units each of which again consists of innumerable molecules. The physiological units are held to make each organism and each species what it is and to have the aptitude to contribute to the construction of the organism in virtue of their polarity. The hypothesis of physiological units is advanced as an explanation of the facts of inheritance in general, and, especially, the generation of living beings from eggs and the regeneration or replacement of lost parts. The organism is able to replace lost parts because the polarity of the units, it is said, causes them to restore the organism to its perfect condition under the directive influence of the whole, which forces the units to arrange themselves in just such a way as is necessary for the perfection of the part in the harmony of the whole. A germ-cell is held to contain small groups of these units which, by their polarity, give to it the power to reproduce the whole.
  • n. According to Bateson, an ultimate element or unit of inheritance, of unknown nature, of which an allelomorph or character-unit is the sensible manifestation.
  • n. In the centesimal method, a grade.
  • n. Acre-foot, a unit used in irrigation; the volume of water required to cover one acre to a depth of one foot, = 43,560 cubic feet, = 1,233.49 cubic meters.
  • n. Ampere, a practical unit of electrical current, = 0.1 c. g. s. unit.
  • n. Ampere (international), the ampere as defined for practical purposes by the International Congress at Chicago in 1893, as the current required to deposit 0.001118 gram of silver in a second of time. This value was subsequently legalized in the United States and was re-adopted by the Electrical Conference in England (1908), although the value 0.0011183 was known to be more nearly correct.
  • n. Ampere-hour, =3,600 coulombs, =360 c. g. s. units (electromagnetic).
  • n. Ampere-second, =1 coulomb.
  • n. Ampere-turn, a unit of magnetomotive force, =4 π/10 c. g. s. units, =1.256637 gilberts.
  • n. Angström unit, =0.0000001 millimeter, =0.0001 micron.
  • n. Arc, = 100 square meters, =1,076.387 square feet.
  • n. Atmosphere, a unit of fluid pressure, = the pressure of a column of mercury 76 centimeters in height, =1,013,240 dynes per square centimeter. Sometimes an atmosphere is defined as a pressure of 1 kilogram per square centimeter.
  • n. Bougie décimale, a unit of intensity of light originally defined as 1/20 of a violle; subsequently (by the Geneva Congress of Photometricians), as equal to 1 hefner.
  • n. Bougie de l'étoile, a unit of intensity of light used in France; the light from a stearin candle burning 10 grams per hour, = 1/7 carcels (approximately).
  • n. British thermal unit, the heat required to raise one pound (avoir.) of water one degree Fahrenheit, = 1,054.90 joules, = 251.996 calories, = 778.104 foot-pounds, = 0.000392982 horse-power hour, = 0.293027 watt-hour.
  • n. Calory, a calorimetric unit; the heat required to raise one gram of water one degree centigrade (also called a gram-calory or small calory), =4.18617 joules, = 3.08777 foot-pounds, =0.003968 British thermal unit, = 0.00116282 watt-hour.
  • n. Candle (British standard), a unit of intensity of light; the light from a spermaceti candle of specified composition, size, and form (see standard candle), = 1.136 Hefner units.
  • n. Candle (German; German Vereinskerze), a unit of intensity of light; the light from a paraffin candle having a diameter of 20 millimeters and a flame height of 50 millimeters, =1.16 … 1.224 Hefner units (approximately), =1.05 British standard candles (approximately).
  • n. Candle (Munich), a unit of intensity of light; the light from a stearin candle of conical form, =0.153 carcel (approximately), =1.17. British standard candles (approximately).
  • n. Candle (star). See bougie de l'étoile (above).
  • n. Candle-foot. See foot-candle (below).
  • n. Candle-meter. See meter-candle (below).
  • n. Carcel, a unit of intensity of light formerly used in France; the light from a lamp of Argand type with mechanical draft, =10.87 … 10.90 Hefner units (approximately), =9.53 British candles (approximately).
  • n. Centimeter, =0.01 meter, =0.393700 inch.
  • n. Centimeter (cubic), =0.001 liter, =0.0610234 cubic inch.
  • n. C. G. S. unit of acceleration, an acceleration of one centimeter per second per second, =0.00101979 of the acceleration due to gravity.
  • n. C. G. S. unit of capacity (electromagnetic), the capacity of a condenser the charge of which at unit potential (c. g. s.) is one c. g. s. unit of quantity or 10 coulombs, = 1 × 109 farads.
  • n. C. G. S. unit of capacity (electrostatic), =1/9 × 10–20 c. g. s. units of capacity of the electromagnetic system (approximately), =1/9 × 10–11 farads (approximately).
  • n. C. G. S. unit of electric charge (electromagnetic), the charge transferred by one c. g. s. unit of current in one second of time, =10 coulombs, =0.00277778 ampere-hour, = 3 × 1010 electrostatic units (approximately).
  • n. C. G. S. unit of electric charge (electrostatic), the charge which in air exerts a force of one dyne on an equal charge at a distance of one centimeter, =1/v c. g. s. units (electromagnetic), =10/V coulombs or 1/3 × 10coulombs (approximately).
  • n. C. G. S. unit of electric current, the current which, flowing in a circular coil of one centimeter radius, produces at the center of the coil a magnetic field of 2μ units intensity, =10 amperes.
  • n. C. G. S. unit of electrical resistance, =1 × 10–9 ohms.
  • n. C. G. S. unit of electromotive force, =1 × 10–8 volts.
  • n. C. G. S. unit of energy, =1 erg, = 0.0000001 joule.
  • n. C. G. S. unit of force, =1 dyne, =0.00101979 of the force due to a gram, = 0 000002248 of the force due to a pound, =0.00007233 poundal.
  • n. C. G. S. unit of inductance, the inductance which gives one c. g. s. unit of electromotive force when the current is changing at the rate of one c. g. s. unit per second, =1 × 10–9 henrys.
  • n. C. G. S. unit of magnetic flux, the flux which acts with a force of one dyne on a unit magnetic pole, = 1 maxwell, = 1 line of force, = 1/4 μ of the flux from a unit pole.
  • n. C. G. S. unit of magnetic induction (or flux density), a flux density of one line of force, or maxwell per square centimeter; the magnetic induction in a field which exerts a force of one dyne upon a unit pole placed in it, = 1 gauss.
  • n. C. G. S. unit of magnetomotive force, the magnetomotive force that gives one c. g. s. unit of magnetic flux through one c. g. s. unit of reluctance, = 1 gilbert, = 10/4 μ ampere-turns.
  • n. C. G. S. unit of permeance (or magnetic conductance), the reciprocal of one unit of reluctance.
  • n. C. G. S. unit of power, = 1 erg per second.
  • n. C. G. S. unit of reluctance (or magnetic resistance), that reluctance (or resistance) through which a c. g. s. unit of magnetomotive force gives a c. g. s. unit of magnetic flux, = 1 oersted.
  • n. C. G. S. unit of velocity, a velocity of one centimeter per second.
  • n. Chain (surveyors'), = 66.00 feet, =20.117 meters.
  • n. Coulomb, a practical unit of electric charge, = 0.1 c. g. s. unit (electromagnetic), = 1 ampere-second, =0.000277778 ampere-hour.
  • n. Coulomb (international), the charge transferred by one international ampere in one second of time.
  • n. Daniell, a former practical unit of electromotive force; the electromotive force of a Daniell cell, = 1.08 to 1.10 volts.
  • n. Day (astronomical), the twenty-four hours from noon to noon (mean solar time).
  • n. Day (calendar day), the twenty-four hours from midnight to midnight (mean solar time).
  • n. Day (civil). Same as calendar day (above).
  • n. Day (mean solar), = 86,400 mean solar seconds, =86,636.55 sidereal seconds, = 1.002737 sidereal days.
  • n. Day (sidereal), = 86,164.1 mean solar seconds, =86,400 sidereal seconds, =0.997269 mean solar day.
  • n. Degree (of arc), =0.0174533 radian.
  • n. Degree (of latitude), =60 nautical miles at equator (approximately), = 69.00 statute miles at 40° lat.
  • n. Degree (of longitude), =60 nautical miles at equator (approximately), =53.05 statute miles at 40° lat.
  • n. Degree (Celsius). Same as a degree centigrade (below).
  • n. Degree (centigrade), = 1/100 of the interval between the ice-point and the steam-point of a thermometer, =9/5 of a degree Fahrenheit.
  • n. Degree (Fahrenheit), = 1/180 of the interval between the ice-point and the steam-point of a thermometer, =5/9 of a degree centigrade.
  • n. Degree (Kelvin; K), = one degree on the absolute scale of temperatures the intervals of which are the same as those of the centigrade scale while the zero is at —273° C.
  • n. Degree (Réaumur), = 1/80 of the Interval between the ice-point and the steam-point of a thermometer, = 5/4 of a degree centigrade, =9/4 of a degree Fahrenheit.
  • n. Dyne, a unit of force; the force which, acting on a mass of one gram, produces an acceleration per second of one centimeter per second, =0.00007233 poundal. A dyne is equivalent to the following gravitational forces at sea-level in latitude 45°:=0.00101979 gram,=0.000–00224825 pound.
  • n. Erg, the c. g. s. unit of energy; the work done by a force of one dyne acting through a distance of one centimeter, = 0.0000001 joule.
  • n. Farad, a unit of electrical capacity, = 9 × 1011 c. g. s. units of the electrostatic system (approximately).
  • n. Farad (international), the capacity represented by the ratio of one international coulomb divided by one international volt. The microfarad in common use is one millionth of this quantity.
  • n. Fathom (British), =0.001 nautical mile, =6.080 feet, =1.8532 meters.
  • n. Fathom (United States), =6.00 feet, = 1.8288 meters.
  • n. Foot (British), =12 inches, = 30.4801 centimeters.
  • n. Foot (cubic), =28,317.0 cubic centimeters, =7.48052 gallons (United States).
  • n. Foot-candle, a unit of illumination; the illumination from a candle at a distance of one foot, =12.2 luxes (approximately).
  • n. Foot-pound, a gravitational unit of work, =1.35573 joules, =0.323859 calory, = 0.000376591 watt-hour, = 0.000000–505051 horse-power hour.
  • n. Furlong, =660 feet, =201.17 meters.
  • n. Gallon (liquid; United States), =3,785.43 cubic centimeters, =231 cubic inches.
  • n. Gallon (imperial), =4,545.9361 cubic centimeters,=277.410 cubic inches, =0.00594586 cubic yard.
  • n. Gauss, a unit of magnetic induction or flux density, = 1 c. g. s. unit, = 1 maxwell or line of force per square centimeter, =6.45163 maxwells per square inch.
  • n. Gilbert, a unit of magnetomotive force, = 1 c. g. s. unit, =10/4π = .7958 ampere-turn.
  • n. Grade, a unit of angular measure, =0.01 quadrant, = 0.015708 radian.
  • n. Grain,=0.0647989 gram.
  • n. Gram, = 15.432356 grains, =0.0352740 oz. (avoir.), =0.0022046 pound (avoir.).
  • n. Gram (taken as a unit of force at sea-level in latitude 45°), = 980.600 dynes, = 0.0709265 poundal.
  • n. Gram-centimeter, a gravitational unit of work; the work required to lift one gram one centimeter against gravity, =980.60 ergs in lat. 45°.
  • n. Gram-molecule, that weight of a substance in grams which equals numerically its molecular weight.
  • n. Hand, a unit used in measuring the height at which horses stand, =4.0 inches.
  • n. Hectare, = 10,000 square meters, =2.47104 acres.
  • n. Hectoliter, = 100 liters, =26.4170 gallons (U. S.), =3.53145 cubic feet.
  • n. Hefner, the unit of intensity of light commonly accepted as the primary standard in photometry (see hefner), =0.88 British standard candle, =0.89 … 1.026 bougies décimales (approximately).
  • n. Hefner (spherical), a unit of flux of light; the total flux from a source of light of one hefner intensity, =12.5664 lumens.
  • n. Henry, a practical unit of inductance; an inductance such that the induced electromotive force is one international volt, while the rate of variation of the inducing current is one international ampere per second, = 1 quadrant, = 1 secohm, = 1 × 109 c. g. s. units.
  • n. Horse-power, =745.650 watts. =33,000 foot-pounds per minute, =42.4108 British thermal units per minute, = 10,687.3 calories per minute, = 1.01387 metric horse-power.
  • n. Horse-power (metric), = 0.735448 kilowatt, = 0.986318 horse-power.
  • n. Horse-power hour, = 2,684,340 joules, = 1,980,000 foot-pounds, =2,544.65 British thermal units, = 745.650 watt-hours, = 641,240 calories.
  • n. Hundredweight (long), = 112 pounds (avoir.).
  • n. Hundredweight (short), = 100 pounds (avoir.),=45.35924 kilograms.
  • n. Inch, =.083333 foot, =2.540005 centimeters.
  • n. Inch (circular), a unit of cross-section, =1,000,000 circular mils, = 0.785398 square inch, = 5.067090 square centimeters.
  • n. Inch (miners), a unit of flow of water. = 1.5 cubic feet per minute. =0.000707925 cubic meter per second.
  • n. Joule, a practical unit of energy, = 10,000,000 ergs, = 0.737612 foot-pound, =0.238882 calory.
  • n. Kapp line, a practical unit of magnetic flux =6,000 maxwells.
  • n. Kilo-calory (also called large calory), = 1,000 calories.
  • n. Kilodyne, = 1,000 dynes.
  • n. Kilogram, = 1,000 grams, =35.2740 ounces (avoir.), =2.20462 pounds (avoir.).
  • n. Kilogram (taken as a unit of force at sea-level in latitude 45°), =980,600 dynes, =70,9265 poundals.
  • n. Kilogram-meter, a gravitational unit of work, = 9.80596 joules, = 7.23300 foot-pounds, = 2.34247 calories, = 0.00272388 watt-hour.
  • n. Kilometer, = 1,000 meters, =3,280.83 feet, =0.621370 mile.
  • n. Kilowatt, = 1,000 watts, = 1.34111 horse-power, = 44,256.7 foot-pounds per minute, = 56.8776 British thermal units per minute.
  • n. Kilowatt-hour, = 1,000 watt-hours, = 3,600,000 joules, = 3,412.66 British thermal units, = 859,975 calories, = 1.34111 horse-power hours.
  • n. Kine, a unit of velocity, =one centimeter per second.
  • n. Knot or nautical mile, =6,080.27 feet, = 1,853.25 meters,= 1′ of the earth's circumference.
  • n. Light-year, a unit of length used in expressing the distance of fixed stars from the earth, = 9.467 × 1012 kilometers, =5.8825 × 1012 miles.
  • n. Line of force (magnetic), a unit of flux, =1 maxwell or c. g s. unit.
  • n. Link, a unit of length used in surveying, =7.920 inches, =20.117 centimeters.
  • n. Liter, =1,000 cubic centimeters, =1.05668 quarts (United States), = 0.0013079 cubic yard.
  • n. Lumen, a unit of flux of light; the flux from a source of one hefner intensity per unit of solid angle; the flux from one hefner which is comprised within a cone which subtends a surface of one square meter at a radius of one meter, =0.079577 of the total flux from a hefner.
  • n. Lumen-hour, a unit of quantity of light (or more properly of luminous energy); one lumen of flux for one hour.
  • n. Lux, a unit of illumination; the illumination from one hefner at a distance of one meter, =0.0818 foot-candle.
  • n. Matthiesen's unit of electrical conductivity, = 592,768 mho-cubic centimeter units.
  • n. Maxwell, a unit of magnetic flux, = 1 c. g. s. unit, = 1 line of force, = 1/4π of the flux from a unit pole.
  • n. Megadyne, =1,000,000 dynes.
  • n. Megamho, the reciprocal of a microhm.
  • n. Megaohm. Same as megohm (below).
  • n. Megavolt, = 1,000,000 volts.
  • n. Megohm, a unit of electrical resistance, = 1,000,000 ohms.
  • n. Meter, = 100 centimeters, =39.37000 inches, = 3.28083 feet.
  • n. Meter (cubic), = 61,023.4 cubic inches. =264,170 gallons (United States), = 35.3145 cubic feet, = 1.30794 cubic yards.
  • n. Meter-candle, a unit of illumination; the illumination from a candle at a distance of one meter,=1 lux (approximately), =0.0818 foot-candle.
  • n. Meter-kilogram, a practical unit of torque; the torque exerted by a force corresponding to the weight of one kilogram acting at the end of an arm one meter in length.
  • n. Mho, a practical unit of electrical conductance; for unvarying direct currents it is the reciprocal of the ohm, =1 × 10 c. g. s. units.
  • n. Mho (in alternating currents), a practical unit of admittance. Admittance in mhos is effective amperes divided by effective volte.
  • n. Mho (in alternating circuits), a unit of susceptance. Susceptance in mhos is wattless amperes divided by volts.
  • n. Mho-cubic centimeter unit (Hering). See unit of electrical conductivity (below).
  • n. Micro-ampere, =0.000001 ampere.
  • n. Microdyne, a unit of force, =0.000001 dyne.
  • n. Microfarad, the practical unit commonly used for the measure of electrical capacity, =9 × 105 c. g. s. units of the electrostatic system (approximately), = 0.000001 farad.
  • n. Microhenry (of inductance), = 0.000001 henry, = 1,000 c. g. s. units.
  • n. Microhm, a unit of electrical resistance, =0.000001 ohm, = 1,000 c. g. s. units.
  • n. Micron (μ), = 0.001 millimeter, =10,000 Ångström units.
  • n. Microvolt, =0.000001 volt, = 100 c. g. s. units.
  • n. Mil, =0.001 inch, =.002540 centimeter.
  • n. Mil (circular), a unit of cross-section, = 0.000001 circular inch, =0.00050671 square millimeter.
  • n. Mile (nautical) or knot, =1.15155 statute miles,=6,080.27 feet, = 1,853.25 meters.
  • n. Mile (statute), = 5,280 feet, =1,609.35 meters.
  • n. Milliampere, =0.001 ampere.
  • n. Milligram, =0.015432 grain.
  • n. Millihenry (of inductance), = 0.001 henry.
  • n. Millimeter, =0.1 centimeter, =0.039370 inch.
  • n. Millimeter (circular), a unit of cross-section, = 1.55000 circular mils, = 0.785398 square millimeter.
  • n. Millimicron (μμ),=0.001μ, =0.000001 millimeter.
  • n. Millivolt, =0.001 volt.
  • n. Mol, = 1 gram-molecule.
  • n. Month (lunar), averages 29.53059 mean solar days.
  • n. Month (synodic), an average lunar month.
  • n. Oersted, a unit of reluctance or magnetic resistance, = 1 c. g. s. unit.
  • n. Ohm, a unit of electrical resistance, = 1 × 109 c. g. s. units.
  • n. Ohm (B. A., or British Association), =0.986699 ohm.
  • n. Ohm (Board of Trade), = 1.01358 B. A. ohms.
  • n. Ohm (international), a practical unit of resistance recommended by the International Congress at Chicago in 1893 and subsequently legalized by the United States Congress. It is the resistance at 0° C. of a column of pure mercury of uniform cross-section and 106.3 centimeters in length, weighing 14.4521 grams.
  • n. Ohm (legal), =0.997178 ohm.
  • n. Ohm (true), = 1 × 109 c. g. s. units.
  • n. Ounce (avoir.), =28.3495 grams, =437.500 grains, =0.062500 pound (avoir.)
  • n. Ounce (fluid; British), =28.41227 cubic centimeters, = 1.73381 cubic inches.
  • n. Ounce (fluid; United States), =29.5737 cubic centimeters, =1.80469 cubic inches.
  • n. Ounce (troy), =480 grains, =31.1035 grams.
  • n. Pint (imperial), = 568.245 cubic centimeters, =34.6762 cubic inches, = 1.20091 United States pints (liquid).
  • n. Pint (dry; United States), = 1.16365 liquid pints (United States), =0.968972 imperial pint, =550.614 cubic centimeters.
  • n. Pint (liquid; United States), =473.179 cubic centimeters, =28.875 cubic inches, =0.859367 pint (dry; United States), =0.832702 imperial pint.
  • n. Poucelet, a unit of power, =100 kilogram-meters per second, =0.9806 kilowatt, = 1.31509 horse-power.
  • n. Pound (avoir.),=7,000 grains, =453.5924 grams.
  • n. Pound (taken as a unit of force at sea-level in latitude 45°), =444,791 dynes,=32.1717 poundals.
  • n. Pound (troy),=5,760 grains, =373.242 grams.
  • n. Pound-foot, a practical unit of torque; the torque exerted by a force corresponding to the weight of one pound acting at the end of an arm one foot in length.
  • n. Poundal, a unit of force; a force which, acting upon a mass of one pound, produces an acceleration per second of one foot per second, =13,825.5 dynes. The poundal corresponds to the force exerted by 0.031083 pound or 14.099 grams at sea-level in latitude 45°.
  • n. Pyr, a unit of intensity of light, = 1 bougie décimale.

Etymologies

Back-formation from unity.
(American Heritage® Dictionary of the English Language, Fourth Edition)
Formerly unite, a later form of unity; see unity. (Wiktionary)

Examples

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