mad vs madness

mad is not a noun while madness is a noun.

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

mad (noun)	madness (noun)
	unrestrained excitement or enthusiasm
	the quality of being rash and foolish
	a feeling of intense anger
	obsolete terms for legal insanity
	an acute viral disease of the nervous system of warm-blooded animals (usually transmitted by the bite of a rabid animal); rabies is fatal if the virus reaches the brain

mad (adjective)	madness (adjective)
roused to anger
very foolish
affected with madness or insanity
marked by uncontrolled excitement or emotion