WordNet sense 1 (South American holly; leaves used in making a drink like tea):

Ilex paraguariensis, Paraguay tea

WordNet sense 2 (a fellow member of a team):

teammate

WordNet sense 3 (a person's partner in marriage):

partner, spouse, better half, married person

WordNet sense 4 (the officer below the master on a commercial ship):

first mate

WordNet sense 5 (an exact duplicate):

match

WordNet sense 6 (make love):

couple, pair

WordNet sense 7 (bring two objects, ideas, or people together):

twin

WordNet sense 8 (place an opponent's king under an attack from which it cannot escape and thus ending the game):

checkmate