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

  • n. The numerical symbol 0; a cipher.
  • n. Mathematics The identity element for addition.
  • n. Mathematics A cardinal number indicating the absence of any or all units under consideration.
  • n. Mathematics An ordinal number indicating an initial point or origin.
  • n. Mathematics An argument at which the value of a function vanishes.
  • n. The temperature indicated by the numeral 0 on a thermometer.
  • n. A sight setting that enables a firearm to shoot on target.
  • n. Informal One having no influence or importance; a nonentity: a manager who was a total zero.
  • n. The lowest point: His prospects were approaching zero.
  • n. A zero-coupon bond.
  • n. Informal Nothing; nil: Today I accomplished zero.
  • adj. Of, relating to, or being zero.
  • adj. Having no measurable or otherwise determinable value.
  • adj. Informal Absent, inoperative, or irrelevant in specified circumstances: "The town has . . . practically no opportunities for amusement, zero culture” ( Robert M. Adams).
  • adj. Meteorology Designating a ceiling not more than 16 meters (52 feet) high.
  • adj. Meteorology Limited in horizontal visibility to no more than 55 meters (180 feet).
  • 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.
  • transitive v. To adjust (an instrument or a device) to zero value.
  • zero in To aim or concentrate firepower on an exact target location.
  • zero in To adjust the aim or sight of by repeated firings.
  • zero in To converge intently; close in: The children zeroed in on the display of toys in the store window.
  • zero out To eliminate (a budget or budget item) by cutting off funding.
  • zero out To reduce to zero.

from Wiktionary, Creative Commons Attribution/Share-Alike License

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

from the GNU version of the Collaborative International Dictionary of English

  • n. A cipher; nothing; naught.
  • n. The point from which the graduation of a scale, as of a thermometer, commences.
  • n. Fig.: The lowest point; the point of exhaustion.

from The Century Dictionary and Cyclopedia

  • n. In function-theory, a value of x which makes the function vanish.
  • 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.
  • n. Cipher; the figure 0, which stands for naught in the Arabic notation for numbers.
  • n. The defect of all quantity considered as quantity; the origin of measurement stated as at a distance from itself; nothing, quantitatively regarded.
  • n. Hence—3. Figuratively, the bottom of the scale; the lowest point or ebb; a state of nullity or inanition.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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


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

Italian, from alteration of Medieval Latin zephirum, from Arabic ṣifr, nothing, cipher; see cipher.

from Wiktionary, Creative Commons Attribution/Share-Alike License

From French zéro, from Italian zero, from Medieval Latin zephirum, from Arabic صفر (ṣifr, "nothing, cipher").


  • The term "zero tolerance" came into popular usage during the Reagan presidency when Congress passed the Drug-Free Schools and Communities Act.

    Alan Singer: The School-to-Prison Pipeline

  • The potential of electric vehicles and fuel cell vehicles to dramatically cut emissions from cars is tremendous, though the term "zero emissions motoring" needs to be treated with caution.

    BBC News - Home

  • Over the past two months in particular, Turkey's leaders have been adjusting a foreign policy that went under the rubric "zero problems with neighbors" to changes forced by the Arab Spring, analysts say.

    Turkey Seizes Libyan Bank Assets

  • Consider This: An intriguing image characterizes this unusual name, but its similarity to the word zero may be holding it back.

    5-Star Baby Name Advisor

  • The term zero-energy home was coined by the Department of Energy as part of a program to create technologies for homes that would produce all of their own energy by 2010.

    Living Free and Easy

  • But it raises the question of whether zero is a continuation of the natural numbers, or a separate type of entity.

    None is, none are: Grammar according to Clarkson « Motivated Grammar

  • Mr. Bratton, who ended his stint as Los Angeles police chief last year and joined a private security firm, advocated what he termed a zero-tolerance policy toward petty and minor crimes combined with a reliance on crime statistics to guide policing.

    Tenderloin Crackdown Sparks Backlash

  • What McCain is trying to do, Wolf, is trying to balance his stanch support for hard-hit Americans with what he calls zero tolerance for Washington and Wall Street being asleep at the switch.

    CNN Transcript Sep 17, 2008

  • In 1994, founder Ray Anderson started his company on its goal as a “restorative enterprise,” which he described as zero net pollution and 100% recycling by 2020.

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  • President Bush said it's unrealistic to expect what he calls zero violence in Iraq.

    CNN Transcript Jun 14, 2006


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  • Zero, a Word sometimes us'd especially among the French, for a Cipher or Nought (0).

    Phillips's New World of Words, 1706

    June 8, 2011

  • Zero is both a robot in Sonic the Hedgehog and a candy bar.

    January 28, 2009

  • Zero is both a thing and a lack of a thing.

    January 28, 2009

  • Ooh I dunno, the law of the playground is a code above the shots of (wo)man.

    January 28, 2009

  • Can this be cured with a cootie shot?

    January 28, 2009

  • Zero the hero.

    First the worst.

    Second the best.

    Third the one with the hairy chest.

    Fourth the horse with the tomato-sauce.

    January 28, 2009

  • Hero or Zero?

    September 6, 2007

  • "My reflection, dirty mirror

    There's no connection to myself

    I'm your lover, I'm your zero

    I'm in the face of your dreams of glass"

    January 10, 2007