(baseball, informal) A double play, two outs recorded in one play
(baseball, informal) A doubleheader, two games played on the same day between the same teams
(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.
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.
(archaic) 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.