impairment vs impair

impairment is a noun but impair is not a noun.

Word	Noun	Adjective	Verb	Adverb
impairment	Yes	No	No	No
impair	No	No	Yes	No

impairment (noun)	impair (noun)
damage that results in a reduction of strength or quality
the act of making something futile and useless (as by routine)
the occurrence of a change for the worse
the condition of being unable to perform as a consequence of physical or mental unfitness
a symptom of reduced quality or strength

impairment (verb)	impair (verb)
	make worse or less effective
	make imperfect