plural of positive assortative mating

(Britain, slang) An individual who has few or no friends.

(nautical) In the merchant navy, the officer who is second in command to the captain, and whose primary duties include managing the maintenance and upkeep of the vessel.

One who shares an office with another

plural of office mate

(chess) The quickest possible checkmate in the game of chess.

plural of first mate

(nautical) An officer on a merchant ship next in rank to the captain and responsible to the captain for the safety and security of the ship.

(politics) A candidate on a joint ticket. / (politics) A candidate for the US vice-presidency. / One of a pair of ships with coordinated, often reciprocal, sailing schedules.

(baseball) One who plays in the same battery, either the pitcher or the catcher.