loneliness vs solitariness

loneliness and solitariness both are nouns.

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

As nouns, loneliness and solitariness are synonyms defined as:

Other synonyms of loneliness include aloneness, lonesomeness.

As nouns, loneliness and solitariness are synonyms defined as:

loneliness and solitariness: the state of being alone in solitary isolation

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