Meaning

• Two similar or identical things taken together; often followed by of.

  "I couldn't decide which of the pair of designer shirts I preferred, so I bought the pair."

• Two people in a relationship, partnership or friendship.

  "Spouses should make a great pair."

• 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"

• 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."

• A poker hand that contains two cards of identical rank, which cannot also count as a better hand.

• A score of zero runs (a duck) in both innings of a two-innings match.

• A double play, two outs recorded in one play.

  "They turned a pair to end the fifth."

• A doubleheader, two games played on the same day between the same teams

  "The Pirates took a pair from the Phillies."

• A boat for two sweep rowers.

• A pair of breasts

  "She's got a gorgeous pair."

• 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.

• 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."

• A number of things resembling one another, or belonging together; a set.

• (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.

Meaning

• To group into one or more sets of two.

  "The wedding guests were paired boy/girl and groom's party/bride's party."

• To bring two (animals, notably dogs) together for mating.

• To engage (oneself) with another of opposite opinions not to vote on a particular question or class of questions.

• To suit; to fit, as a counterpart.