1. (adj)baleful, baneful deadly or sinister
"the Florida eagles have a fierce baleful look"
2. (adj)baleful, forbidding, menacing, minacious, minatory, ominous, sinister, threatening threatening or foreshadowingevil 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"