ternary vs tierce

ternary and tierce both are nouns.

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

As nouns, ternary and tierce are synonyms defined as:

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

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

ternary (noun)	tierce (noun)
the cardinal number that is the sum of one and one and one	one of three equal parts of a divisible whole
	the cardinal number that is the sum of one and one and one
	the third canonical hour; about 9 a.m.

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