feverous vs ill

feverous is not a noun while ill is a noun.

Word	Noun	Adjective	Verb	Adverb
feverous	No	Yes	No	No
ill	Yes	Yes	No	Yes

feverous (noun)	ill (noun)
	an often persistent bodily disorder or disease; a cause for complaining

feverous (adjective)	ill (adjective)
having or affected by a fever	affected by an impairment of normal physical or mental function
	distressing
	resulting in suffering or adversity
	indicating hostility or enmity
	presaging ill fortune

feverous (adverb)	ill (adverb)
	(`ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
	with difficulty or inconvenience; scarcely or hardly
	unfavorably or with disapproval