zero

1 of 3

noun

ze·​ro ˈzir-(ˌ)ō  ˈzē-(ˌ)rō 

plural zeros also zeroes

1

a

: 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

3

a(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

5

a

: a state of total absence or neutrality

b

: the lowest point : nadir

6

: something arbitrarily or conveniently designated zero

zero

2 of 3

adjective

1

a

: 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

2

a

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

zero

3 of 3

verb

zeroed; zeroing; zeroes

transitive verb

1

: to determine or adjust the zero of

zero a rifle

2

a

: 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

Synonyms

Noun

• nothing
• nil

Examples of zero in a Sentence

Noun

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.

Recent Examples on the Web

Noun

Strong technical leaders don't just translate between the world of zeros and ones and the world of dollars and cents. —Meeky Hwang, Forbes.com, 25 Aug. 2025

That is, they are composed of on/off switches strung together in logic circuits that process data as a string of binary ones and zeros. —New Atlas, 21 Aug. 2025

Adjective

Silent and durable by design Built with a patented hydrogen-safe structure, the airship is designed to fly quietly and safely in various conditions, including sub-zero Arctic environments. —Kapil Kajal, Interesting Engineering, 2 Sep. 2025

The city of Fort Worth is offering monetary relief to homeowners still dealing with the aftereffects of February 2021 winter storm, which brought sub-zero temperatures to Texas, resulting in tens of billions of dollars in statewide property damage. —Matthew Adams, Fort Worth Star-Telegram, 26 Aug. 2025

Verb

This style of research—wandering around, then zeroing in—is a version of the ancient fox-hedgehog distinction made famous by Isaiah Berlin. —Dan Rockmore, New Yorker, 9 Aug. 2025

The arena cameras zeroed on a fan tearful over the outcome. —Marc Ramirez, USA Today, 3 Aug. 2025

Word History

Etymology

Noun

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

First Known Use

Noun

1598, in the meaning defined at sense 1a

Adjective

1821, in the meaning defined at sense 1a

Verb

1911, in the meaning defined at transitive sense 1

Phrases Containing zero

• absolute zero
• from zero
• ground zero
• net-zero
• patient zero
• sub-zero
• zero-base
• zero-based
• zero coupon
• zero-day
• zero grade
• zero gravity
• zero hour
• zero in on
• zero out
• zero-sum
• zero-sum game
• zero tillage
• zero tolerance
• zero vector
• zero waste
• zero-zero

Rhymes for zero

• biro
• spiro
• nonzero
• subzero
• superhero

Kids Definition

zero

1 of 3 noun

ze·​ro ˈzē-rō 

ˈzi(ə)r-ō

plural zeros also zeroes

1

: the numerical symbol 0 meaning the absence of all magnitude or quantity see number

2

a

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

b

: a value or reading of zero

especially : the temperature represented by zero on a thermometer

3

: something or someone of no importance

4

: the lowest point

zero

2 of 3 adjective

1

a

: of, relating to, or being a zero

b

: having no size or quantity

zero growth

2

: showing no change in the word form

"sheep" is a noun with a zero plural

zero

3 of 3 verb

1

: to find out or adjust the zero of (as a balance)

2

: to aim or concentrate on a target or goal

zero in on my problems with algebra

Medical Definition

zero

noun

ze·​ro ˈzē-(ˌ)rō  ˈzi(ə)r-(ˌ)ō 

plural zeros also zeroes

1

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

2

a

: 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