sinister

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”

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

on or starting from the wearer''s left

• “bar sinister”