doubleton vs couple

doubleton and couple both are nouns.

Word	Noun	Adjective	Verb	Adverb
doubleton	Yes	No	No	No
couple	Yes	No	Yes	No

As nouns, couple is a hypernym of doubleton; that is, couple is a word with a broader meaning than doubleton:

doubleton: (bridge) a pair of playing cards that are the only cards in their suit in the hand dealt to a player
couple: two items of the same kind

Other hypernyms of doubleton include brace, couplet, distich, duad, duet, duo, dyad, pair, span, twain, twosome, yoke.

doubleton (noun)	couple (noun)
(bridge) a pair of playing cards that are the only cards in their suit in the hand dealt to a player	a pair who associate with one another
	a pair of people who live together
	(physics) something joined by two equal and opposite forces that act along parallel lines
	two items of the same kind
	a small indefinite number

doubleton (verb)	couple (verb)
	engage in sexual intercourse
	link together
	bring two objects, ideas, or people together
	form a pair or pairs