Mate, n.
Etymology: [Perhaps for older make a companion; cf. also OD. maet companion, mate, D. maat. Cf. Make a companion, Match a mate.]
1. One who customarily associates with another; a companion; an associate; any object which is associated or combined with a similar object.
2. Hence, specifically, a husband or wife; and among the lower animals, one of a pair associated for propagation and the care of their young.
3. A suitable companion; a match; an equal. Ye knew me once no mate For you; there sitting where you durst not soar. Milton.
4. (Naut.)
1 more senses
An officer in a merchant vessel ranking next below the captain. If there are more than one bearing the title, they are called, respectively, first mate, second mate, third mate, etc. In the navy, a subordinate officer or assistant; as, master's mate; surgeon's mate.
6 other Webster entries under this spelling
Mate, n.
The Paraguay tea, being the dried leaf of the Brazilian holly (Ilex Paraguensis). The infusion has a pleasant odor, with an agreeable bitter taste, and is much used for tea in South America.
Mate, n.
(Chess)
Same as Checkmate.
Mate, a.
See 2d Mat. [Obs.] Chaucer.
Mate, v. t.
1. To confuse; to confound. [Obs.] Shak.
2. To checkmate.
Mate, v. t. [imp. & p. p. Mated; p. pr. & vb. n. Mating.]
1. To match; to marry. If she be mated with an equal husband. Shak.
2. To match one's self against; to oppose as equal; to compete with. There is no passion in the mind of man so weak but it mates and masters the fear of death. Bacon. I, . . . in the way of loyalty and truth, . . . Dare mate a sounder man than Surrey can be. Shak.
Mate, v. i.
To be or become a mate or mates, especially in sexual companionship; as, some birds mate for life; this bird will not mate with that one.
Shades of meaning
Fernald has no entry of its own for mate; he lists it under associate.
He lists it without comment; the entries above explain its neighbors.