crazy vs impractical

crazy is a noun but impractical is not a noun.

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

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

crazy (adjective)	impractical (adjective)
intensely enthusiastic about or preoccupied with	not practical; not workable or not given to practical matters
possessed by inordinate excitement	not practical or realizable; speculative
foolish; totally unsound
affected with madness or insanity
bizarre or fantastic