Antonyms of adj ominous

2 senses of ominous

Sense 1
baleful, forbidding, menacing, minacious, minatory, ominous, sinister, threatening -- (threatening or foreshadowing evil or tragic developments; "a baleful look"; "forbidding thunderclouds"; "his tone became menacing"; "ominous rumblings of discontent"; "sinister storm clouds"; "a sinister smile"; "his threatening behavior"; "ugly black clouds"; "the situation became ugly")

INDIRECT (VIA alarming) -> unalarming -- (not alarming; assuaging alarm)

Sense 2
ill, inauspicious, ominous -- (presaging ill fortune; "ill omens"; "ill predictions"; "my words with inauspicious thunderings shook heaven"- P.B.Shelley; "a dead and ominous silence prevailed"; "a by-election at a time highly unpropitious for the Government")

INDIRECT (VIA unpropitious) -> propitious -- (presenting favorable circumstances; likely to result in or show signs of success; "propitious omens"; "propitious gales speeded us along"; "a propitious alignment of planets for space exploration")

Similarity of adj ominous

2 senses of ominous

Sense 1
baleful, forbidding, menacing, minacious, minatory, ominous, sinister, threatening -- (threatening or foreshadowing evil or tragic developments; "a baleful look"; "forbidding thunderclouds"; "his tone became menacing"; "ominous rumblings of discontent"; "sinister storm clouds"; "a sinister smile"; "his threatening behavior"; "ugly black clouds"; "the situation became ugly")
       => alarming (vs. unalarming) -- (frightening because of an awareness of danger)

Sense 2
ill, inauspicious, ominous -- (presaging ill fortune; "ill omens"; "ill predictions"; "my words with inauspicious thunderings shook heaven"- P.B.Shelley; "a dead and ominous silence prevailed"; "a by-election at a time highly unpropitious for the Government")
       => unpropitious (vs. propitious) -- (not propitious)