Definitions
1.nounA fellow, comrade, colleague, partner or someone with whom something is shared, e.g. shipmate, classmate.
2.noun(especially of a non-human animal) A breeding partner.
3.nounA friend, usually of the same sex."He's my best mate."
4.nounFriendly term of address to a stranger, usually male, of similar age"Excuse me, mate, have you got the time?"
5.nounIn naval ranks, a non-commissioned officer or his subordinate (e.g. Boatswain's Mate, Gunner's Mate, Sailmaker's Mate, etc).
6.nounA ship's officer, subordinate to the master on a commercial ship.
7.nounA first mate.
8.nounA technical assistant in certain trades (e.g. gasfitter's mate, plumber's mate); sometimes an apprentice.
9.nounThe other member of a matched pair of objects."I found one of the socks I wanted to wear, but I couldn't find its mate."
10.nounA suitable companion; a match; an equal.
11.verbTo match, fit together without space between."The pieces of the puzzle mate perfectly."
12.verbTo copulate.
13.verbTo pair in order to raise offspring
14.verbTo arrange in matched pairs.
15.verbTo introduce (animals) together for the purpose of breeding.
16.verb(of an animal) To copulate with.
17.verbTo marry; to match (a person).
18.verbTo match oneself against; to oppose as equal; to compete with.
19.verbTo fit (objects) together without space between.
20.verbTo move (a space shuttle orbiter) onto the back of an aircraft that can carry it.