sinister

Synonyms: adverse apocalyptic bad baleful baneful blackhearted corrupt deleterious dire disastrous dishonest disquieting doomful evil foreboding harmful hurtful ill-boding inauspicious injurious lowering malefic malevolent malign malignant mischievous obnoxious ominous pernicious perverse poisonous portentous threatening unfavorable unfortunate unlucky unpropitious woeful

Antonyms: benevolent kind nice