noun, plural pairs, pair.
  1. two identical, similar, or corresponding things that are matched for use together: a pair of gloves; a pair of earrings.
  2. something consisting of or regarded as having two parts or pieces joined together: a pair of scissors; a pair of slacks.
  3. two individuals who are similar or in some way associated: a pair of liars; a pair of seal pups.
  4. a married, engaged, or dating couple.
  5. two mated animals.
  6. a span or team: a pair of horses.
  7. Government.
    1. two members on opposite sides in a deliberative body who for convenience, as to permit absence, arrange together to forgo voting on a given occasion.
    2. the arrangement thus made.
  8. Cards.
    1. two playing cards of the same denomination without regard to suit or color.
    2. pairs,two card players who are matched together against different contestants.
  9. pairs, pair skating.
  10. Also called kinematic pair. Mechanics. two parts or pieces so connected that they mutually constrain relative motion.
  11. Philately. two postage stamps joined together either vertically or horizontally.
  12. a set or combination of more than two objects forming a collective whole: a pair of beads.
verb (used with object)
  1. to arrange or designate in pairs or groups of two: She paired dancers for the waltz contest.
  2. to form into a pair, as by matching, joining, etc.; match; couple: to pair freshly washed socks.
  3. (of animals) to cause to mate.
verb (used without object)
  1. to separate into pairs or groups of two (usually followed by off ): to pair off for a procession.
  2. to form a pair or pairs.
  3. to be a member of a pair.
  4. to match with or resemble another.
  5. to unite in close association with another, as in a business partnership, friendship, marriage, etc.
  6. (of animals) to mate.
  7. Government. (in a deliberative body) to form or arrange a pair.
  1. grow a pair, Slang: Vulgar. to act in a stereotypically manly way, as by being brave: Stop the whining and grow a pair!

Origin of pair

1250–1300; Middle English paire < Old French < Latin pāria, plural (taken as feminine singular) of pār a pair. See par1
Related formspair·wise, adverbun·paired, adjectivewell-paired, adjective
Can be confusedpair pare payer pearcouple pair several (see synonym study at the current entry)

Synonym study

1. Pair, brace, couple, span, yoke are terms for groups of two. Pair is used of two things naturally or habitually associated in use, or necessary to each other to make a complete set: a pair of dice. It is used also of one thing composed of two similar and complementary parts: a pair of trousers. Brace is a hunter's term, used of a pair of dogs, ducks, etc., or a pair of pistols or slugs: a brace of partridges. In couple the idea of combination or interdependence has become greatly weakened; it may be used loosely for two of anything ( a couple of apples ), and even for more than two: I have to see a couple of people. Span is used of a matched pair of horses harnessed together side by side. Yoke applies to the two animals hitched together under a yoke for drawing and pulling: a yoke of oxen.

Usage note

When used without a modifier, pairs is the only possible plural: Pairs of skaters glided over the ice. When modified by a number, pairs is the more common form, especially referring to persons: Six pairs of masked dancers led the procession. The unmarked plural pair is used mainly in reference to inanimate objects or nonhumans: He has three pair (or pairs ) of loafers. Two pair (or pairs ) of barn owls have nested on our property.
Pair signifying two individuals can take either a singular or plural verb, but it is usually followed by a plural verb and referred to by a plural pronoun: The guilty pair have not been seen since their escape.
In the sense “a set or combination of more than two objects forming a collective whole,” pair occurs chiefly in fixed phrases: a pair of beads; a pair of stairs. This use is now somewhat old-fashioned. See also collective noun, couple. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for pairwise

Historical Examples of pairwise

British Dictionary definitions for pairwise


noun plural pairs or functioning as singular or plural pair
  1. two identical or similar things matched for use togethera pair of socks
  2. two persons, animals, things, etc, used or grouped togethera pair of horses; a pair of scoundrels
  3. an object considered to be two identical or similar things joined togethera pair of trousers
  4. two people joined in love or marriage
  5. a male and a female animal of the same species, esp such animals kept for breeding purposes
  6. parliamentary procedure
    1. two opposed members who both agree not to vote on a specified motion or for a specific period of time
    2. the agreement so made
  7. two playing cards of the same rank or denominationa pair of threes
  8. one member of a matching pairI can't find the pair to this glove
  9. cricket a pair of spectacles (the cricketing term)See spectacles (def. 2)
  10. rowing See pair-oar
  11. British and US dialect a group or set of more than two
  12. logic maths
    1. a set with two members
    2. an ordered set with two members
  1. (often foll by off) to arrange or fall into groups of twos
  2. to group or be grouped in matching pairsto pair socks
  3. to join or be joined in marriage; mate or couple
  4. (when tr, usually passive) parliamentary procedure to form or cause to form a pair18 members were paired for the last vote
See also pairs

Word Origin for pair

C13: from Old French paire, from Latin paria equal (things), from pār equal


Like other collective nouns, pair takes a singular or a plural verb according to whether it is seen as a unit or as a collection of two things: the pair are said to dislike each other; a pair of good shoes is essential


  1. a Scot word for poor
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

Word Origin and History for pairwise



mid-13c., "two of a kind coupled in use," from Old French paire "pair, couple," and directly from Medieval Latin paria "equals," neuter plural of Latin par (genitive paris) "a pair, counterpart, equal," noun use of par (adj.) "equal, equal-sized, well-matched" (see par (n.)). Originally of things. Of persons from late 14c. Meaning "a woman's breasts" is attested from 1922. Pair bond (v.) is first attested 1940, in reference to birds mating.



"to come together with another; be mated or married" (intransitive), also "to make a pair by matching" (transitive), c.1600, from pair (n.). These senses now often are distinguished by pair off (c.1803) for the former and pair up (1908) for the latter. Related: Paired; pairing.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with pairwise


In addition to the idiom beginning with pair

  • pair off

also see:

  • show one's (a clean pair of) heels
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.