trenchancy vs trenchant

trenchancy is a noun but trenchant is not a noun.

Word	Noun	Adjective	Verb	Adverb
trenchancy	Yes	No	No	No
trenchant	No	Yes	No	No

trenchancy (noun)	trenchant (noun)
keenness and forcefulness of thought or expression or intellect

trenchancy (adjective)	trenchant (adjective)
	clearly or sharply defined to the mind
	characterized by or full of force and vigor
	having keenness and forcefulness and penetration in thought, expression, or intellect