[ nuhm-ber ]
See synonyms for: numbernumberednumberingnumbers on

  1. a numeral or group of numerals.

  2. the sum, total, count, or aggregate of a collection of people or things: The number of children experiencing homelessness in the city has risen alarmingly.

  1. a word or symbol, or a combination of words or symbols, used in counting or in noting a total.

  2. the particular numeral assigned to an object or, sometimes, a person, indicating its place in a series: house number;license number;jersey number.

  3. one of a series of things or people distinguished by or marked with numerals: Number 5's order is ready to be delivered.

  4. a code of numerals, letters, or a combination of these assigned to a particular telephone: Did you call the right number?

  5. quantity as composed of units or individuals: The governor put forth a plan to increase the number of eligible voters.

  6. the count or quantity of a collection or company: Their number was more than 20,000.

  7. numbers,

    • a considerable amount or quantity; many: Numbers flocked to the city to see the parade.

    • metrical feet; verse.

    • musical periods, measures, or groups of notes.

    • Informal. the figures representing the actual cost, expense, profit, etc.: We won't make a decision until we see the numbers.

    • Obsolete. arithmetic.

  8. numerical strength or superiority; complement: The garrison is not up to its full number.

  9. a single or distinct performance within a show, as a song or dance: The comic routine followed the dance number.

  10. a single part of a program made up of a group of similar parts: For her third number she played a nocturne.

  11. any of a collection of poems or songs.

  12. a tune or arrangement for singing or dancing.

  13. a distinct part of an extended musical work or one in a sequence of compositions.

  14. conformity in music or verse to regular beat or measure; rhythm.

  15. a single part of a book published in a series of parts.

  16. a single issue of a periodical: The bookcase contained several numbers of a popular magazine.

  17. Grammar. a category of noun, verb, or adjective inflection found in many languages, such as English, Latin, and Arabic, used to indicate whether a word has one or more than one referent. There may be a two-way distinction in number, as between singular and plural, three-way, as between singular, dual, and plural, or a more complex system.

  18. Informal. a person; individual: Why don't you go talk to the attractive number standing at the bar?

  19. Informal. an article of merchandise, especially of clothing, offered for sale: Put those leather numbers in the display window.

  20. mathematics regarded as a system, a basic concept, and a mode of thought: Number is the basis of science.

verb (used with object)
  1. to mark with or distinguish by numeral:Number each of the definitions.

  2. to ascertain the number of; count.

  1. to total or amount to: The manuscript already numbers 425 pages.

  2. to consider or include in a collection or group: I number myself among his friends.

  3. to count over one by one: to number one's blessings.

  4. to mention individually or one by one; list; enumerate: They numbered the highlights of their trip at length.

  5. to set or fix the number of; limit in number; make few in number: The sick old man's days are numbered.

  6. to live or have lived (a number of years).

  7. to apportion or divide by counting (used with off): The players were numbered off into two teams.

verb (used without object)
  1. to make a total; reach an amount: Casualties numbered in the thousands.

  2. to be numbered or included (usually followed by among or with): Several eminent scientists number among his friends.

  1. to count.

Idioms about number

  1. a number of, an imprecisely reckoned collection of more than a few; several: In a number of states, like Ohio, Iowa, and North Carolina, early voting has already begun.

  2. any number of, an imprecisely reckoned but large or diverse collection: The island is home to any number of artistic residents from around the world.

  1. by the numbers,

    • according to standard procedure, rules, customs, etc.; orthodoxly; by the book: We're going to run things here by the numbers.

    • together or in unison to a called-out count: The class involves calisthenics by the numbers.

  2. do a number on, Slang.

    • to undermine, defeat, humiliate, or criticize thoroughly: The committee really did a number on the mayor's proposal.

    • to discuss or discourse about, especially in an entertaining way: She could do a number on anything from dentistry to the Bomb.

  3. do one's number,

    • to give a performance; perform: It's time for you to get on stage and do your number.

    • Slang. to behave in a predictable or customary manner: Whenever I call, he does his number about being too busy to talk.

  4. get / have someone's number, Informal. to become informed about someone's real motives, character, intentions, etc.: He was only interested in her fortune, but she got his number fast.

  5. have someone's number on it, Slang. to be thought of as the instrument of fate in the death of a person: That bullet had his number on it.

  6. one's number is / was / will be up, Slang.

    • one is (was, will be) in serious trouble.

    • one is (was, will be) on the point of death: Convinced that her number was up anyway, she refused to see doctors.

  7. without number, of unknown or countless number; vast: The night sky was filled with stars without number.

Origin of number

First recorded in 1250–1300; 1940–45 for def. 20; Middle English noun nombre, nomber, number, from Old French nombre, numbre, from Latin numerus; verb derivative of the noun

synonym study For number

2. Number, sum both imply the total of two or more units. Number applies to the result of a count or estimate in which the units are considered as individuals; it is used of groups of persons or things: to have a number of items on the agenda. Sum applies to the result of addition, in which only the total is considered: a large sum of money.

Grammar notes for number

2. As a collective noun, number, when preceded by a, is most often treated as a plural: A number of legislators have voiced their dissent. When preceded by the, it is usually used as a singular: The number of legislators present was small. See also collective noun.

confusables note For number

See amount,

Other words for number

Other words from number

  • num·ber·a·ble, adjective
  • num·ber·er, noun
  • de·num·ber, verb (used with object)
  • mis·num·ber, verb
  • pre·num·ber, verb (used with object), noun
  • re·num·ber, verb (used with object)
  • sub·num·ber, noun

Words that may be confused with number

Words Nearby number Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use number in a sentence

British Dictionary definitions for number


/ (ˈnʌmbə) /

  1. a concept of quantity that is or can be derived from a single unit, the sum of a collection of units, or zero. Every number occupies a unique position in a sequence, enabling it to be used in counting. It can be assigned to one or more sets that can be arranged in a hierarchical classification: every number is a complex number; a complex number is either an imaginary number or a real number, and the latter can be a rational number or an irrational number; a rational number is either an integer or a fraction, while an irrational number can be a transcendental number or an algebraic number: See complex number, imaginary number, real number, rational number, irrational number, integer, fraction, transcendental number, algebraic number See also cardinal number, ordinal number

  2. the symbol used to represent a number; numeral

  1. a numeral or string of numerals used to identify a person or thing, esp in numerical order: a telephone number

  2. the person or thing so identified or designated: she was number seven in the race

  3. the sum or quantity of equal or similar units or things: a large number of people

  4. one of a series, as of a magazine or periodical; issue

    • a self-contained piece of pop or jazz music

    • a self-contained part of an opera or other musical score, esp one for the stage

  5. a group or band of people, esp an exclusive group: he was not one of our number

  6. slang a person, esp a woman: who's that nice little number?

  7. informal an admired article, esp an item of clothing for a woman: that little number is by Dior

  8. slang a cannabis cigarette: roll another number

  9. a grammatical category for the variation in form of nouns, pronouns, and any words agreeing with them, depending on how many persons or things are referred to, esp as singular or plural in number and in some languages dual or trial

  10. any number of several or many

  11. by numbers military (of a drill procedure, etc) performed step by step, each move being made on the call of a number

  12. do a number on someone US slang to manipulate or trick someone

  13. get someone's number or have someone's number informal to discover someone's true character or intentions

  14. in numbers in large numbers; numerously

  15. one's number is up British informal one is finished; one is ruined or about to die

  16. without number or beyond number of too great a quantity to be counted; innumerable

verb(mainly tr)
  1. to assign a number to

  2. to add up to; total

  1. (also intr) to list (items) one by one; enumerate

  2. (also intr) to put or be put into a group, category, etc: they were numbered among the worst hit

  3. to limit the number of: his days were numbered

Origin of number

C13: from Old French nombre, from Latin numerus

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for number


[ nŭmbər ]

  1. A member of the set of positive integers. Each number is one of a series of unique symbols, each of which has exactly one predecessor except the first symbol in the series (1), and none of which are the predecessor of more than one number.

  2. A member of any of the further sets of mathematical objects defined in terms of such numbers, such as negative integers, real numbers, and complex numbers.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for number


The grammatical category that classifies a noun, pronoun, or verb as singular or plural. Woman, it, and is are singular; women, they, and are are plural.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Other Idioms and Phrases with number


In addition to the idiom beginning with number

  • number is up, one's

also see:

  • a number of
  • any number of
  • back number
  • by the numbers
  • crunch numbers
  • days are numbered
  • do a job (number) on
  • get (have) someone's number
  • hot number
  • in round numbers
  • look out for (number one)
  • opposite number
  • safety in numbers

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.