solitariness vs loneliness

solitariness and loneliness both are nouns.

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

As nouns, solitariness and loneliness are synonyms defined as:

Other synonyms of solitariness include aloneness, lonesomeness.

As nouns, solitariness and loneliness are synonyms defined as:

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

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