adjective
seriously threatening disaster
a sinister plot
Synonyms: baleful, malefic, maleficent, malign; compare ominous
Related Word: fateful, ill-omened, inauspicious, ominous, portentous, unpropitious; apocalyptic, dire, doomful, ill-boding, threatening; lowering, menacing; evil, malicious
Contrasted words: harmless, innocent, innocuous