ze·ro | \ˈzē-(ˌ)rō, ˈzir-(ˌ)ō\
plural zeros also zeroes

Definition of zero 

(Entry 1 of 3)

1a : the arithmetical symbol 0 or 0̸ denoting the absence of all magnitude or quantity

b : additive identity specifically : the number between the set of all negative numbers and the set of all positive numbers

c : a value of an independent variable that makes a function equal to zero +2 and −2 are zeros of f(x)=x2−4

2 : the absence of a measurable quantity — see Table of Numbers

3a(1) : the point of departure in reckoning specifically : the point from which the graduation of a scale (as of a thermometer) begins

(2) : the temperature represented by the zero mark on a thermometer

b : the setting or adjustment of the sights of a firearm that causes it to shoot to point of aim at a desired range

4 : an insignificant person or thing : nonentity

5a : a state of total absence or neutrality

b : the lowest point : nadir

6 : something arbitrarily or conveniently designated zero



Definition of zero (Entry 2 of 3)

1a : of, relating to, or being a zero

b : having no magnitude or quantity : not any zero growth zero tolerance

c(1) : having no phonetic manifestation the zero modification in the past tense of cut

(2) : having no modified inflectional form a zero plural

2a of a cloud ceiling : limiting vision to 50 feet (15 meters) or less

b of horizontal visibility : limited to 165 feet (50.3 meters) or less


zeroed; zeroing; zeroes

Definition of zero (Entry 3 of 3)

transitive verb

1 : to determine or adjust the zero of zero a rifle

2a : to concentrate firepower on the exact range of usually used with in

b : to bring to bear on the exact range of a target usually used with in

intransitive verb

1 : to adjust fire on a specific target usually used with in

2 : to close in on or focus attention on an objective usually used with in investigators are zeroing in on a suspect

Keep scrolling for more

Examples of zero in a Sentence


Two minus two equals zero. It's supposed to fall below zero tonight. The temperature is 10° above zero. They are working to reduce the mortality rate to zero.
See More

Recent Examples on the Web: Noun

To put that in perspective, an octillion is a one with 27 zeros after it. Jared Gilmour, miamiherald, "Teacher was raped and murdered in 1992. Gum left at a school just caught the killer, Pa. cops say," 27 June 2018 Please note: your account number is numeric only, 5-8 digits long, and does not require the magazine code (such as SCA) or the leading zeros that appear on the mailing label. Scientific American, "Frequently Asked Questions," 19 June 2018 The bullpen nailed it down for the rookie with zeroes over the final three innings. Craig Davis,, "Trevor Richards notches first big-league win as Marlins down Giants again," 13 June 2018 And Tom Irwin, who is vicious — like a rooster seeing a speck of blood — he just zeros in for the kill! Nina Metz,, "My worst moment: 'Chicago P.D.'s' Amy Morton recalls the job that required her to dress as a sea nymph," 12 June 2018 After abandoning grand plans to build its own self-driving car, Apple is working with Volkswagen to put its zeros and ones on wheels, the Times reports. Alex Davies, WIRED, "This Week in the Future of Cars: Burn, Baby, Burn," 25 May 2018 Here, Riley zeroes in on the performances black employees in Silicon Valley and beyond must undertake just to exist in the same space as their white colleagues and bosses. Hannah Giorgis, The Atlantic, "Sorry to Bother You Has an Eerily Familiar Villain," 10 July 2018 Thousands of existing Southwest Portland addresses have leading zeroes, which can be confusing for dispatchers trying to direct emergency personnel in the event of a crisis. Andrew Theen,, "Plan to shift thousands of addresses to 'South Portland' heads to City Council," 30 May 2018 In avoiding a three-game sweep Sunday, the Orioles (20-50) finally put some crooked letters on an Oriole Park scoreboard that had shown nothing but zeros and occasional ones. Eduardo A. Encina,, "Orioles beat Marlins, 10-4, to end 9-game slide, earn first home win since Mother's Day," 17 June 2018

Recent Examples on the Web: Adjective

There is a decidedly non-zero possibility that the federal government will shut down on Friday night. Sy Mukherjee, Fortune, "Brainstorm Health: Human CRISPR Trials, Hospital Run Drug Company, CHIP Extension," 18 Jan. 2018 Davis has played in just 13 NFL games, made zero appearances last year, and posted a passer rating of 66.2 in his three performances with the Browns in 2015. Matt Calkins, The Seattle Times, "Criticize Colin Kaepernick? Fine. But don’t withhold a job from him," 5 June 2017 There’s absolutely zero evidence that dogs or cats can contract or transmit the virus. Patty Khuly, miamiherald, "Should I worry that my dog or cat will get Zika?," 10 May 2017

Recent Examples on the Web: Verb

Early, the birds poured into the flat, most zeroing in on the open hole near the spinning-wing decoy. Shannon Tompkins, Houston Chronicle, "Concealment, patience key for hunters as waterfowl season ends," 17 Jan. 2018 The question most election observers are zeroing in on isn’t necessarily if Republican Lesko is going to lose but whether Democrats can narrow the margin by which Trump and Franks won. Tara Golshan, Vox, "Debbie Lesko and Hiral Tipirneni face off for Trent Franks’s seat in Arizona’s special election," 23 Apr. 2018 Under the bill, these resources would have been zeroed out. Mandy Mclaren, The Courier-Journal, "Why Kentucky teachers are fighting so hard over the vetoed budget bill," 10 Apr. 2018 The Trump administration’s budget proposal released last week again zeroed out funding for the earthquake early warning program administered by the U.S. Geological Survey. Rong-gong Lin Ii,, "Trump again seeks to end funding for earthquake early warning system," 20 Feb. 2018 Since its beginnings over 400 years ago, microscopy has made leaps and bounds—even zeroing in on individual atoms. Jason Daley, Smithsonian, "Watch Cells Move Within Living Animals in This Breathtaking Footage," 30 Apr. 2018 Same goes for the San Diego search, which ESPN also reported has zeroed in on Utah Valley's Mark Pope. Jeff Greer, The Courier-Journal, "At the Final Four, David Padgett hopes to find 'the right opportunity'," 1 Apr. 2018 Officers zeroed in on his location about 10:15 a.m. after a woman found the suspect in her shed. Lyndsay Winkley,, "Suspected burglar arrested after trying to hide in attic," 25 Mar. 2018 On Wednesday evening, The Washington Post reported that special counsel Robert Mueller is zeroing in on Blackwater founder and all-around bad guy Erik Prince. Alex Shephard, The New Republic, "If there was “no collusion” why did the Trump transition team work so hard to set up a back channel with Russia?," 8 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'zero.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of zero


1598, in the meaning defined at sense 1a


1810, in the meaning defined at sense 1a


1913, in the meaning defined at transitive sense 1

History and Etymology for zero


French or Italian; French zéro, from Italian zero, from Medieval Latin zephirum, from Arabic ṣifr

Keep scrolling for more

Learn More about zero

Phrases Related to zero

from zero

zero in on

zero out

zero tolerance

Statistics for zero

Last Updated

19 Oct 2018

Look-up Popularity

Time Traveler for zero

The first known use of zero was in 1598

See more words from the same year

Keep scrolling for more

More Definitions for zero



English Language Learners Definition of zero

 (Entry 1 of 3)

: the number 0

: the temperature shown by the zero mark on a thermometer

: nothing at all



English Language Learners Definition of zero (Entry 2 of 3)

: not any



English Language Learners Definition of zero (Entry 3 of 3)

: to set (a measuring device, such as a scale) so that it reads 0


ze·ro | \ˈzē-rō, ˈzir-ō\
plural zeros or zeroes

Kids Definition of zero

1 : the numerical symbol 0 meaning the absence of all size or quantity

2 : the point on a scale (as on a thermometer) from which measurements are made

3 : the temperature shown by the zero mark on a thermometer

4 : a total lack of anything : nothing His contribution was zero.


ze·ro | \ˈzē-(ˌ)rō, ˈzi(ə)r-(ˌ)ō \
plural zeros also zeroes

Medical Definition of zero 

1 : the arithmetical symbol 0 or 0̸ denoting the absence of all magnitude or quantity

2a : the point of departure in reckoning specifically : the point from which the graduation of a scale (as of a thermometer) begins

b : the temperature represented by the zero mark on a thermometer

Keep scrolling for more

More from Merriam-Webster on zero

Thesaurus: All synonyms and antonyms for zero

Spanish Central: Translation of zero

Nglish: Translation of zero for Spanish Speakers

Britannica English: Translation of zero for Arabic Speakers Encyclopedia article about zero

Comments on zero

What made you want to look up zero? Please tell us where you read or heard it (including the quote, if possible).


a state of commotion or excitement

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
Spell It

Can you spell these 10 commonly misspelled words?

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!