triad vs deuce-ace

triad and deuce-ace both are nouns.

Word	Noun	Adjective	Verb	Adverb
triad	Yes	No	No	No
deuce-ace	Yes	No	No	No

As nouns, triad and deuce-ace are synonyms defined as:

triad and deuce-ace: the cardinal number that is the sum of one and one and one

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

triad (noun)	deuce-ace (noun)
a three-note major or minor chord; a note and its third and fifth tones	the cardinal number that is the sum of one and one and one
three people considered as a unit
a set of three similar things considered as a unit
the cardinal number that is the sum of one and one and one