tercet vs threesome

tercet and threesome both are nouns.

Word	Noun	Adjective	Verb	Adverb
tercet	Yes	No	No	No
threesome	Yes	No	No	No

As nouns, tercet and threesome are synonyms defined as:

tercet and threesome: the cardinal number that is the sum of one and one and one

Other synonyms of tercet include 3, deuce-ace, III, leash, ternary, ternion, terzetto, three, tierce, trey, triad, trine, trinity, trio, triplet, troika.

tercet (noun)	threesome (noun)
the cardinal number that is the sum of one and one and one	three people considered as a unit
	the cardinal number that is the sum of one and one and one