ternary vs tercet

ternary and tercet both are nouns.

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

As nouns, ternary and tercet are synonyms defined as:

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

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

ternary (noun)	tercet (noun)
the cardinal number that is the sum of one and one and one	the cardinal number that is the sum of one and one and one

ternary (adjective)	tercet (adjective)
having three units or components or elements