unpropitiousness vs inauspiciousness

unpropitiousness and inauspiciousness both are nouns.

Word	Noun	Adjective	Verb	Adverb
unpropitiousness	Yes	No	No	No
inauspiciousness	Yes	No	No	No

As nouns, unpropitiousness and inauspiciousness are synonyms defined as:

unpropitiousness and inauspiciousness: the quality of suggesting an unsuccessful result

unpropitiousness (noun)	inauspiciousness (noun)
the quality of suggesting an unsuccessful result	the quality of suggesting an unsuccessful result