truncation vs truncate

truncation is a noun but truncate is not a noun.

Word	Noun	Adjective	Verb	Adverb
truncation	Yes	No	No	No
truncate	No	Yes	Yes	No

truncation (noun)	truncate (noun)
the act of cutting short
the replacement of an edge or solid angle (as in cutting a gemstone) by a plane (especially by a plane that is equally inclined to the adjacent faces)
the property of being truncated or short

truncation (adjective)	truncate (adjective)
	terminating abruptly by having or as if having an end or point cut off

truncation (verb)	truncate (verb)
	make shorter as if by cutting off
	approximate by ignoring all terms beyond a chosen one
	replace a corner by a plane