loony vs crazy

loony and crazy both are nouns.

Word	Noun	Adjective	Verb	Adverb
loony	Yes	Yes	No	No
crazy	Yes	Yes	No	No

As nouns, loony and crazy are synonyms defined as:

Other synonyms of loony include looney, nutcase, weirdo.

loony (noun)	crazy (noun)
someone deranged and possibly dangerous	someone deranged and possibly dangerous

loony (adjective)	crazy (adjective)
informal or slang terms for mentally irregular	intensely enthusiastic about or preoccupied with
	possessed by inordinate excitement
	foolish; totally unsound
	affected with madness or insanity
	bizarre or fantastic