Threatening or foreshadowing evil or tragic developments. Synonyms: baleful, forbidding, menacing, minatory, ominous, sinister, threatening. "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"
