a. Repelling approach; repulsive; raising abhorrence, aversion, or dislike; disagreeable; prohibiting or interdicting; as, a forbidding aspect; a forbidding formality; a forbidding air.
(adj) threatening or foreshadowing evil or tragic developments, Syn. ominous, minacious, menacing, forbidding, threatening, sinister, minatory, Example: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
(adj) harshly uninviting or formidable in manner or appearance; ; ; ; - J.M.Barrie, Syn. forbidding, grim, Example: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