pair

Etymology 1

From Middle English paire, from Old French paire, from Latin paria (“equals”), neuter plural of par (“pair”). Related to pār (“equal”, adj). Compare Saterland Frisian Poor (“pair”), West Frisian pear (“pair”), Dutch paar (“pair”), German Paar (“pair”).

noun

1. Two similar or identical things taken together; often followed by of.
   Where we once sent love letters in a sealed envelope, or stuck photographs of our children in a family album, now such private material is despatched to servers and clouds operated by people we don't know and will never meet. Perhaps we assume that our name, address and search preferences will be viewed by some unseen pair of corporate eyes, probably not human, and don't mind that much. 2013-06-14, Jonathan Freedland, “Obama's once hip brand is now tainted”, in The Guardian Weekly, volume 189, number 1, page 18
   I couldn't decide which of the pair of designer shirts I preferred, so I bought the pair.
   1. One of the constituent items that make up a pair.
      [S]he had finished the second sock, and pulled its pair out of the bag before handing them to her husband. 1992, Elizabeth Jane Howard, Marking Time: Volume 2 of The Cazalet Chronicle, page 74
      Must be good at athletics, home repairs, making mince interesting and finding the pair to the other glove. 1996, Kathy Lette, Mad Cows, page 219
2. Two people in a relationship, partnership or friendship.
   Spouses should make a great pair.
3. Used with binary nouns (often in the plural to indicate multiple instances, since such nouns are plural only, except in some technical contexts)
   a pair of scissors; two pairs of spectacles; several pairs of jeans
4. A couple of working animals attached to work together, as by a yoke.
   A pair is harder to drive than two mounts with separate riders.
5. (card games) A poker hand that contains two cards of identical rank, which cannot also count as a better hand.
6. (cricket) A score of zero runs (a duck) in both innings of a two-innings match.
7. (baseball, informal) A double play, two outs recorded in one play.
   They turned a pair to end the fifth.
8. (baseball, informal) A doubleheader, two games played on the same day between the same teams
   The Pirates took a pair from the Phillies.
9. (rowing) A boat for two sweep rowers.
10. (slang) A pair of breasts
    She's got a gorgeous pair.
11. (slang) A pair of testicles
    Grow a pair, mate.
12. (Australia, politics) The exclusion of one member of a parliamentary party from a vote, if a member of the other party is absent for important personal reasons.
13. Two members of opposite parties or opinion, as in a parliamentary body, who mutually agree not to vote on a given question, or on issues of a party nature during a specified time.
    There were two pairs on the final vote.
14. (archaic) A number of things resembling one another, or belonging together; a set.
15. (kinematics) In a mechanism, two elements, or bodies, which are so applied to each other as to mutually constrain relative motion; named in accordance with the motion it permits, as in turning pair, sliding pair, twisting pair.

verb

1. (transitive) To group into one or more sets of two.
   The wedding guests were paired boy/girl and groom's party/bride's party.
   Brown as I am, an Ethiopian dame / Inspired young Perseus with a gen’rous flame; / Turtles and doves of diff’ring hues unite, / And glossy jet is paired with shining white. a. 1744, Alexander Pope, “Sappho to Phaon”, in John Wilson Croker, editor, The Works of Alexander Pope, new edition, volume I, J. Murray, published 1871, pages 94–95
2. (computing) to link two electronic devices wirelessly together, especially through a protocol such as Bluetooth
   It was not possible to pair my smartphone with an incompatible smartwatch.
   If your computer has a built-in, non-Microsoft transceiver, you can pair the device directly to the computer by using your computer’s Bluetooth software configuration program but without using the Microsoft Bluetooth transceiver. 2015, Microsoft, “How-to: Keyboards”, in http://www.microsoft.com, retrieved 2015-02-21
3. (transitive) To bring two (animals, notably dogs) together for mating.
4. (intransitive) To come together for mating.
   The raven, in short, when he pairs, which he does at the earliest moment permitted by the laws of ravendom, pairs for life […] 1883, Alexander Stewart, Nether Lochaber, page 112
5. (politics, slang) To engage (oneself) with another of opposite opinions not to vote on a particular question or class of questions.
6. (intransitive) To suit; to fit, as a counterpart.
   My Heart was made to fit and pair with thine, / Simple and plain, and fraught with artleſs Tenderneſs; / Form’d to receive one Love, and only one, / But pleas’d and proud, and dearly fond of that, / It knows not what there can be in Variety, / And would not if it could. 1707, Nicholas Rowe, The Royal Convert, 2nd edition, Jacob Tonson, published 1714, page 46

Etymology 2

From Middle English pairen, peiren, shortened form of apeiren, empeiren, from Old French empeirier, empoirier, from Late Latin peiōrō.

verb

1. (obsolete, transitive) To impair, to make worse.
   Why dreghis þou þis dole, & deris þi seluyn? / Lefe of þis Langore, as my lefe brother, / Þat puttes þe to payne and peires þi sight. Why endure this misery, and hurt yourself? / End this disease, my dear brother, / That pains you and impairs your sight. a. 1376?, Sir Hugh Eglintoun (uncertain), transl., edited by George Panton, The “Gest Hystoriale” of the Destruction of Troy, N. Trübner & Co., translation of Historia destructionis Troiae by Guido delle Colonne (in Medieval Latin), published 1869, page 117
2. (obsolete, intransitive) To become worse, to deteriorate.