inauspicious vs ominous

inauspicious and ominous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
inauspicious	No	Yes	No	No
ominous	No	Yes	No	No

As adjectives, inauspicious and ominous are synonyms defined as:

Other synonyms of inauspicious include ill.

inauspicious (adjective)	ominous (adjective)
not auspicious; boding ill	threatening or foreshadowing evil or tragic developments
contrary to your interests or welfare	presaging ill fortune
presaging ill fortune