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" ;

2. (

• black ,
• dark ,
• sinister

) stemming from evil characteristics or forces; wicked or dishonorable; "black deeds"; "a black lie"; "his black heart has concocted yet another black deed"; "Darth Vader of the dark side"; "a dark purpose"; "dark undercurrents of ethnic hostility"; "the scheme of some sinister intelligence bent on punishing him"-Thomas Hardy ;

3. (

• sinister

) on or starting from the wearer's left; "bar sinister" ;