triplet vs tercet

triplet and tercet both are nouns.

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

As nouns, triplet and tercet are synonyms defined as:

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

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

triplet (noun)	tercet (noun)
a set of three similar things considered as a unit	the cardinal number that is the sum of one and one and one
one of three offspring born at the same time from the same pregnancy
the cardinal number that is the sum of one and one and one