loneliness vs lonely

loneliness is a noun but lonely is not a noun.

Word	Noun	Adjective	Verb	Adverb
loneliness	Yes	No	No	No
lonely	No	Yes	No	No

loneliness (noun)	lonely (noun)
a disposition toward being alone
sadness resulting from being forsaken or abandoned
the state of being alone in solitary isolation

loneliness (adjective)	lonely (adjective)
	marked by dejection from being alone
	lacking companions or companionship
	devoid of creatures
	characterized by or preferring solitude