triplex vs treble

triplex is not a noun while treble is a noun.

Word	Noun	Adjective	Verb	Adverb
triplex	No	Yes	No	No
treble	Yes	Yes	Yes	No

As adjectives, triplex and treble are synonyms defined as:

Other synonyms of triplex include ternary, triple.

triplex (noun)	treble (noun)
	the pitch range of the highest female voice

triplex (adjective)	treble (adjective)
having three units or components or elements	having or denoting a high range
	three times as great or many
	having three units or components or elements
	having more than one decidedly dissimilar aspects or qualities

triplex (verb)	treble (verb)
	increase threefold
	sing treble