mad vs crazy

mad is not a noun while crazy is a noun.

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

As adjectives, mad and crazy are synonyms defined as:

Other synonyms of mad include brainsick, demented, disturbed, sick, unbalanced, unhinged.

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

mad (adjective)	crazy (adjective)
roused to anger	intensely enthusiastic about or preoccupied with
very foolish	possessed by inordinate excitement
affected with madness or insanity	foolish; totally unsound
marked by uncontrolled excitement or emotion	affected with madness or insanity
	bizarre or fantastic