from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The numerical symbol 0; a cipher.
  • noun The identity element for addition.
  • noun A cardinal number indicating the absence of any or all units under consideration.
  • noun An ordinal number indicating an initial point or origin.
  • noun An argument at which the value of a function vanishes.
  • noun The temperature indicated by the numeral 0 on a thermometer.
  • noun A sight setting that enables a firearm to shoot on target.
  • noun Informal One having no influence or importance; a nonentity.
  • noun The lowest point.
  • noun Informal Nothing; nil.
  • adjective Of, relating to, or being zero.
  • adjective Having no measurable or otherwise determinable value.
  • adjective Informal Absent, inoperative, or irrelevant in specified circumstances.
  • adjective Designating a ceiling not more than 16 meters (52 feet) high.
  • adjective Limited in horizontal visibility to no more than 55 meters (180 feet).
  • adjective 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 verb To adjust (an instrument or a device) to zero value.

from The Century Dictionary.

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

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Arith.) A cipher; nothing; naught.
  • noun The point from which the graduation of a scale, as of a thermometer, commences.
  • noun Fig.: The lowest point; the point of exhaustion.
  • noun See under Absolute.
  • noun (Physics) a method of comparing, or measuring, forces, electric currents, etc., by so opposing them that the pointer of an indicating apparatus, or the needle of a galvanometer, remains at, or is brought to, zero, as contrasted with methods in which the deflection is observed directly; -- called also null method.
  • noun the point indicating zero, or the commencement of a scale or reckoning.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun cardinal The cardinal number occurring before one and that denotes no quantity or amount at all, represented in Arabic numerals as 0.
  • noun The numeric symbol that represents the cardinal number zero.
  • noun The digit 0 in the decimal, binary, and all other base numbering systems.
  • noun informal, uncountable Nothing, or none.
  • noun The value of a magnitude corresponding to the cardinal number zero.
  • noun The point on a scale at which numbering or measurement originates.
  • noun mathematics A value of the independent variables of a function, for which the function is equal to zero.
  • noun mathematics, algebra The additive identity element of a monoid or greater algebraic structure, particularly a group or ring.
  • noun slang A person of little or no importance.
  • noun military A Mitsubishi A6M Zero, a long range fighter aircraft operated by the Japanese Navy Air Service from 1940 to 1945.
  • noun A setting of calibrated instruments such as a firearm.
  • noun finance A security which has a zero coupon (paying no periodic interest).
  • adjective informal, used with noun none


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.

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  • 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.

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  • 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.

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

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  • 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.

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

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  • 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.

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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