bridge partner vs cooperator

bridge partner and cooperator both are nouns.

Word	Noun	Adjective	Verb	Adverb
bridge partner	Yes	No	No	No
cooperator	Yes	No	No	No

As nouns, cooperator is a hypernym of bridge partner; that is, cooperator is a word with a broader meaning than bridge partner:

bridge partner: one of a pair of bridge players who are on the same side of the game
cooperator: an associate in an activity or endeavor or sphere of common interest

Other hypernyms of bridge partner include bridge player, hand, collaborator, pardner, partner.

bridge partner (noun)	cooperator (noun)
one of a pair of bridge players who are on the same side of the game	an associate in an activity or endeavor or sphere of common interest