noun (used with a singular verb)
 the fourth book of the Old Testament, containing the census of the Israelites after the Exodus from Egypt. Abbreviation: Num.
noun
 a numeral or group of numerals.
 the sum, total, count, or aggregate of a collection of units, or the like: A number of people were hurt in the accident. The number of homeless children in the city has risen alarmingly.
 a word or symbol, or a combination of words or symbols, used in counting or in noting a total.
 the particular numeral assigned to an object so as to designate its place in a series: house number; license number.
 one of a series of things distinguished by or marked with numerals.
 a certain collection, company, or quantity not precisely reckoned, but usually considerable or large: I’ve gone there a number of times.
 the full count of a collection or company.
 a collection or company.
 a quantity of individuals: Their number was more than 20,000.
 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.
 numbers pool(def 1).
 Informal.the figures representing the actual cost, expense, profit, etc.: We won’t make a decision until we see the numbers.
 Obsolete.arithmetic.
 quantity as composed of units: to increase the number of eligible voters.
 numerical strength or superiority; complement: The garrison is not up to its full number.
 a tune or arrangement for singing or dancing.
 a single or distinct performance within a show, as a song or dance: The comic routine followed the dance number.
 a single part of a program made up of a group of similar parts: For her third number she played a nocturne.
 any of a collection of poems or songs.
 a distinct part of an extended musical work or one in a sequence of compositions.
 conformity in music or verse to regular beat or measure; rhythm.
 a single part of a book published in a series of parts.
 a single issue of a periodical: several numbers of a popular magazine.
 a code of numerals, letters, or a combination of these assigned to a particular telephone: Did you call the right number?
 Grammar. a category of noun, verb, or adjective inflection found in many languages, as English, Latin, and Arabic, used to indicate whether a word has one or more than one referent. There may be a twoway distinction in number, as between singular and plural, threeway, as between singular, dual, and plural, or more.
 Informal. person; individual: the attractive number standing at the bar.
 Informal. an article of merchandise, especially of wearing apparel, offered for sale: Put those leather numbers in the display window.
 mathematics regarded as a science, a basic concept, and a mode of thought: Number is the basis of science.
verb (used with object)
 to mark with or distinguish by numbers: Number each of the definitions.
 to amount to or comprise in number; total: The manuscript already numbers 425 pages.
 to consider or include in a number: I number myself among his friends.
 to count over one by one; tell: to number one’s blessings.
 to mention individually or one by one; enumerate: They numbered the highlights of their trip at length.
 to set or fix the number of; limit in number; make few in number: The sick old man’s days are numbered.
 to live or have lived (a number of years).
 to ascertain the number of; count.
 to apportion or divide: The players were numbered into two teams.
verb (used without object)
 to make a total; reach an amount: Casualties numbered in the thousands.
 to be numbered or included (usually followed by among or with): Several eminent scientists number among his friends.
 to count.
 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 calledout count: calisthenics by the numbers.
 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.
 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.
 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.
 have one’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.
 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.
 without number, of unknown or countless number; vast: stars without number.
pl n
 informal financial statisticslet’s look at last year’s numbers
noun
 (functioning as singular) the fourth book of the Old Testament, recording the numbers of the Israelites who followed Moses out of Egypt
noun
 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 numberSee complex number, imaginary number, real number, rational number, irrational number, integer, fraction, transcendental number, algebraic number See also cardinal number, ordinal number
 the symbol used to represent a number; numeral
 a numeral or string of numerals used to identify a person or thing, esp in numerical ordera telephone number
 the person or thing so identified or designatedshe was number seven in the race
 the sum or quantity of equal or similar units or thingsa large number of people
 one of a series, as of a magazine or periodical; issue

 a selfcontained piece of pop or jazz music
 a selfcontained part of an opera or other musical score, esp one for the stage
 a group or band of people, esp an exclusive grouphe was not one of our number
 slang a person, esp a womanwho’s that nice little number?
 informal an admired article, esp an item of clothing for a womanthat little number is by Dior
 slang a cannabis cigaretteroll another number
 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
 any number of several or many
 by numbers military (of a drill procedure, etc) performed step by step, each move being made on the call of a number
 do a number on someone US slang to manipulate or trick someone
 get someone’s number or have someone’s number informal to discover someone’s true character or intentions
 in numbers in large numbers; numerously
 one’s number is up British informal one is finished; one is ruined or about to die
 without number or beyond number of too great a quantity to be counted; innumerable
verb (mainly tr)
 to assign a number to
 to add up to; total
 (also intr) to list (items) one by one; enumerate
 (also intr) to put or be put into a group, category, etcthey were numbered among the worst hit
 to limit the number ofhis days were numbered
c.1300, “to count,” from Old French nombrer “to count, reckon,” from nombre (n.) “number” (see number (n.)). Meaning “to assign a number to” is late 14c.; that of “to ascertain the number of” is from early 15c. Related: Numbered; numbering.
c.1300, “sum, aggregate of a collection,” from AngloFrench noumbre, Old French nombre and directly from Latin numerus “a number, quantity,” from PIE root *nem “to divide, distribute, allot” (related to Greek nemein “to deal out;” see nemesis). Meaning “symbol or figure of arithmatic value” is from late 14c. Meaning “single (numbered) issue of a magazine” is from 1795. The meaning “musical selection” (1885) is from vaudeville theater programs, where acts were marked by a number. Meaning “dialing combination to reach a particular telephone receiver” is from 1879; hence wrong number (1886).
Number one “oneself” is from 1704 (mockItalian form numero uno attested from 1973); the biblical Book of Numbers (c.1400, Latin Numeri, Greek Arithmoi) so called because it begins with a census of the Israelites. Slang number one and number two for “urination” and “defecation” attested from 1902. Number cruncher is 1966, of machines; 1971, of persons. To get or have (someone’s) number “have someone figured out” is attested from 1853. The numbers “illegal lottery” is from 1897, American English.
n.
 A symbol expressive of a certain value or of a specific quantity determined by count.
 The place of any unit in a series.
 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.
 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 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.
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