noun num·ber \ˈnəm-bər\

Definition of number

  1. 1 a (1) :  a sum of units :  total (2) :  complement 1b (3) :  an indefinite usually large total <a number of members were absent> <the number of elderly is rising> (4) plural :  a numerous group :  many (5) :  a numerical preponderance b (1) :  the characteristic of an individual by which it is treated as a unit or of a collection by which it is treated in terms of units (2) :  an ascertainable total <bugs beyond number> c (1) :  a unit belonging to an abstract mathematical system and subject to specified laws of succession, addition, and multiplication; especially :  natural number (2) :  an element (as π) of any of many mathematical systems obtained by extension of or analogy with the natural number system (3) plural :  arithmetic

  2. 2 :  a distinction of word form to denote reference to one or more than one; also :  a form or group of forms so distinguished

  3. 3 plural a (1) :  metrical structure :  meter (2) :  metrical lines :  verses b archaic :  musical sounds :  notes

  4. 4 a :  a word, symbol, letter, or combination of symbols representing a number b :  a numeral or combination of numerals or other symbols used to identify or designate <dialed the wrong number> c (1) :  a member of a sequence or collection designated by especially consecutive numbers (as an issue of a periodical) (2) :  a position in a numbered sequence d :  a group of one kind <not of their number>

  5. 5 :  one singled out from a group :  individual: as a :  girl, woman <met an attractive number at the dance> b (1) :  a musical, theatrical, or literary selection or production (2) :  routine, act c :  stunt, trick d :  an act of transforming or impairing <tripped and did a number on her knee> e :  an item of merchandise and especially clothing

  6. 6 :  insight into a person's ability or character <had my number>

  7. 7 plural but sing or plural in constr a :  a form of lottery in which an individual wagers on the appearance of a certain combination of digits (as in regularly published numbers) —called also numbers game b :  2policy 2a

  8. 8 plural a :  figures representing amounts of money usually in dollars spent, earned, or involved b (1) :  statistics 2; especially :  individual statistics (as of an athlete) (2) :  rating 3c

  9. 9 :  a person represented by a number or considered without regard to individuality <at the university I was just a number>

  10. 10 :  lifetime 1a —used with up <the old feeling that comes to men in combat … that your number was up — Geoffrey Norman>

by the numbers

  1. 1 :  in unison to a specific count or cadence

  2. 2 :  in a systematic, routine, or mechanical manner

Usage Discussion of number

Number is regularly used with count nouns <a large number of mistakes> <any number of times> while amount is mainly used with mass nouns <annual amount of rainfall> <a substantial amount of money>. The use of amount with count nouns has been frequently criticized; it usually occurs when the number of things is thought of as a mass or collection <glad to furnish any amount of black pebbles — New Yorker> <a substantial amount of film offers — Lily Tomlin> or when money is involved <a substantial amount of loans — E. R. Black>.

Examples of number in a sentence

  1. the numbers and letters on a license plate

  2. a three-digit number like 429

  3. Think of a number between one and one hundred.

  4. The number 7{frac3 is greater than the number 7.25.

  5. 2, 4, 6, and 8 are even numbers; 1, 3, 5, and 7 are odd numbers.

  6. Never give out your credit card number to anyone over the phone.

  7. What's the account number on your electricity bill?

  8. The page numbers are on the top corner of each page.

  9. Today's winning lottery numbers are 17, 8, and 46.

  10. I'm waiting for the number 3 bus.

Origin and Etymology of number

Middle English nombre, from Anglo-French, from Latin numerus

First Known Use: 14th century

Other Mathematics and Statistics Terms



verb num·ber

Definition of number



play \-b(ə-)riŋ\
  1. transitive verb
  2. 1 :  count, enumerate

  3. 2 :  to claim as part of a total :  include

  4. 3 :  to restrict to a definite number <your days are numbered>

  5. 4 :  to assign a number to <number the pages>

  6. 5 :  to amount to in number :  total <the crew numbers 100>

  7. intransitive verb
  8. 1 :  to reach a total number

  9. 2 :  to call off numbers in sequence


play \-b(ə-)rə-bəl\ adjective


play \-bər-ər\ noun

Examples of number in a sentence

  1. She numbers and arranges the photographs according to when they were taken.

  2. Each print is signed and numbered by the artist.

  3. The team's coach bought all the players numbered jerseys.

  4. In that year, European settlers in the area numbered nearly 15,000.

  5. The animal, which once numbered in the millions, is now extinct.

  6. He numbers her with the other great poets of the time.

14th Century

First Known Use of number

14th century

NUMBER Defined for English Language Learners



noun num·ber \ˈnəm-bər\

Definition of number for English Language Learners

  • : a word or symbol (such as “five” or “16”) that represents a specific amount or quantity

  • : a number or a set of numbers and other symbols that is used to identify a person or thing

  • : a person who is identified by a number and not treated in a personal or friendly way



verb num·ber

Definition of number for English Language Learners

  • : to give a number to (someone or something in a series) : to label or identify (people or things in a series) with a number

  • : to include (someone or something) as part of a larger group

NUMBER Defined for Kids



noun num·ber \ˈnəm-bər\

Definition of number for Students

  1. 1 :  the total of persons, things, or units taken together :  amount <What is the number of people in the room?>

  2. 2 :  a total that is not specified <… the mermaids come up in extraordinary numbers to play with their bubbles. — J. M. Barrie, Peter Pan>

  3. 3 :  a unit belonging to a mathematical system and subject to its rules <Tell me a number divisible by 2.>

  4. 4 :  a word, symbol, or letter used to represent a mathematical number :  numeral <the number 5>

  5. 5 :  a certain numeral for telling one person or thing from another or from others <a house number>

  6. 6 :  a quality of a word form that shows whether the word is singular or plural <A verb agrees in number with its subject.>

  7. 7 :  one of a series <You're number seven on the waiting list.>

  8. 8 :  a song or dance usually that is part of a larger performance <The band played a catchy number.>



verb num·ber

Definition of number for Students



  1. 1 :  1count 1 <The grains of sand cannot be numbered.>

  2. 2 :  include <I was numbered among the guests.>

  3. 3 :  to limit to a certain number <Vacation days are numbered now.>

  4. 4 :  to give a number to <Number the pages of your journal.>

  5. 5 :  to add up to or have a total of <Our group numbered ten in all.>

Seen and Heard

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