A Quick and Simple Dictionary

pair

1. Noun.  Two similar or identical things taken together; often followed by of.
2. Noun.  Two people in a relationship, partnership (especially sexual) or friendship.
3. Noun.  Used with binary nouns (often in the plural to indicate multiple instances, since such nouns are plurale tantum).
4. Noun.  A couple of working animals attached to work together, as by a yoke.
5. Noun.  (cards) A poker hand that contains of two cards of identical rank, which cannot also count as a better hand.
6. Noun.  (cricket) A score of zero runs (a duck) in both innings of a two-innings match.
7. Noun.  (baseball, informal) A double play, two outs recorded in one play.
8. Noun.  (baseball, informal) A doubleheader, two games played on the same day between the same teams.
9. Noun.  (slang) A pair of breasts.
10. Noun.  (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.
11. Verb.  (transitive) To group into sets of two.
12. Verb.  (transitive) To bring two (animals, notably dogs) together for mating.