forbidding

an official prohibition or edict against something

harshly uninviting or formidable in manner or appearance

• “a dour, self-sacrificing life”
• “a forbidding scowl”
• “a grim man loving duty more than humanity”
• “undoubtedly the grimmest part of him was his iron claw” J.M.Barrie

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”