zero

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The numerical symbol 0; a cipher.
2. n. Mathematics The identity element for addition.
3. n. Mathematics A cardinal number indicating the absence of any or all units under consideration.
4. n. Mathematics An ordinal number indicating an initial point or origin.
5. n. Mathematics An argument at which the value of a function vanishes.
6. n. The temperature indicated by the numeral 0 on a thermometer.
7. n. A sight setting that enables a firearm to shoot on target.
8. n. Informal One having no influence or importance; a nonentity: a manager who was a total zero.
9. n. The lowest point: His prospects were approaching zero.
10. n. A zero-coupon bond.
11. n. Informal Nothing; nil: Today I accomplished zero.
12. adj. Of, relating to, or being zero.
13. adj. Having no measurable or otherwise determinable value.
14. adj. Informal Absent, inoperative, or irrelevant in specified circumstances: "The town has . . . practically no opportunities for amusement, zero culture” ( Robert M. Adams).
15. adj. Meteorology Designating a ceiling not more than 16 meters (52 feet) high.
16. adj. Meteorology Limited in horizontal visibility to no more than 55 meters (180 feet).
17. adj. Linguistics Of or relating to a morpheme that is expected by an established, regular paradigm but has no spoken or written form. Moose has a zero plural; that is, its plural is moose.
18. v. To adjust (an instrument or a device) to zero value.
19. zero in To aim or concentrate firepower on an exact target location.
20. zero in To adjust the aim or sight of by repeated firings.
21. zero in To converge intently; close in: The children zeroed in on the display of toys in the store window.
22. zero out To eliminate (a budget or budget item) by cutting off funding.
23. zero out To reduce to zero.

Century Dictionary and Cyclopedia

1. n. In function-theory, a value of x which makes the function vanish.
2. n. In psychophysics, the temperature at which a thermal stimulus fails to arouse a sensation either of warmth or of cold in the cutaneous organs; the indifference-point of thermal stimulation.
3. n. Cipher; the figure 0, which stands for naught in the Arabic notation for numbers.
4. n. The defect of all quantity considered as quantity; the origin of measurement stated as at a distance from itself; nothing, quantitatively regarded. Upon a thermometer or any similar scale zero is the line from which all the divisions are measured in the positive and negative directions. Upon the centigrade and Réaumur's thermometers, it is the point at which the mercury stands when the thermometer is plunged into a mass of melting ice coarsely pulverized, from which some makers allow the water to drain off, but it is better not to do so. For some years after a thermometer is made the zero is said to rise—that is, the melting-point of ice stands higher and higher upon the scale. Upon the Fahrenheit thermometer the distance on the glass stem between the melting-point of ice and the temperature of steam at one English atmosphere of tension is divided into 180 degrees, and 32 such degrees below the melting-point of ice is marked as zero.
5. n. Hence—3. Figuratively, the bottom of the scale; the lowest point or ebb; a state of nullity or inanition.

Wiktionary

1. n. cardinal The cardinal number occurring before one and that denotes no quantity or amount at all, represented in Arabic numerals as 0.
2. n. The numeric symbol that represents the cardinal number zero.
3. n. The digit 0 in the decimal, binary, and all other base numbering systems.
4. n. informal, uncountable Nothing, or none.
5. n. The value of a magnitude corresponding to the cardinal number zero.
6. n. The point on a scale at which numbering or measurement originates.
7. n. mathematics A value of the independent variables of a function, for which the function is equal to zero.
8. n. mathematics, algebra The additive identity element of a monoid or greater algebraic structure, particularly a group or ring.
9. n. slang A person of little or no importance.
10. n. military A Mitsubishi A6M Zero, a long range fighter aircraft operated by the Japanese Navy Air Service from 1940 to 1945.
11. n. A setting of calibrated instruments such as a firearm.
12. n. finance A security which has a zero coupon (paying no periodic interest).
13. adj. informal, used with noun none
14. adj. meteorology Of a cloud ceiling, limiting vision to 50 feet (15 meters) or less.
15. adj. meteorology Of horizontal visibility, limited to 165 feet (50.3 meters) or less.
16. adj. linguistics Present at an abstract level, but not realized in the data.
17. v. transitive To set a measuring instrument to zero; to calibrate instrument scale to valid zero.
18. v. transitive, computing To change a memory location or range to values of zero; to set a variable in a computer program to zero.
19. v. transitive To cause or set some value or amount to be zero.
20. v. transitive To eliminate; to delete; to overwrite with zeros.
21. v. intransitive To disappear

GNU Webster's 1913

1. n. (Arith.) A cipher; nothing; naught.
2. n. The point from which the graduation of a scale, as of a thermometer, commences.
3. n. Fig.: The lowest point; the point of exhaustion.

WordNet 3.0

1. n. a quantity of no importance
2. adj. of or relating to the null set (a set with no members)
3. n. the sight setting that will cause a projectile to hit the center of the target with no wind blowing
4. adj. indicating the absence of any or all units under consideration
5. n. the point on a scale from which positive or negative numerical quantities can be measured
6. adj. indicating an initial point or origin
7. v. adjust (an instrument or device) to zero value
8. n. a mathematical element that when added to another number yields the same number
9. v. adjust (as by firing under test conditions) the zero of (a gun)
10. adj. having no measurable or otherwise determinable value