impair vs spoil

impair is not a noun while spoil is a noun.

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

As verbs, impair and spoil are synonyms defined as:

Other synonyms of impair include deflower, mar, vitiate.

impair (noun)	spoil (noun)
	the act of stripping and taking by force
	the act of spoiling something by causing damage to it
	(usually plural) valuables taken by violence (especially in war)

impair (verb)	spoil (verb)
make worse or less effective	become unfit for consumption or use
make imperfect	alter from the original
	make imperfect
	destroy and strip of its possession
	have a strong desire or urge to do something
	hinder or prevent (the efforts, plans, or desires) of
	treat with excessive indulgence
	make a mess of, destroy or ruin