madness vs insaneness

madness and insaneness both are nouns.

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

As nouns, madness and insaneness are synonyms defined as:

Other synonyms of madness include lunacy.

madness (noun)	insaneness (noun)
unrestrained excitement or enthusiasm	obsolete terms for legal insanity
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