List of forbidding synonyms and forbidding related words.
Olympian, abhorrent, abominable, aloof, awful, backward, bad, base, bashful, beastly, below contempt, beneath contempt, blank, chilled, chilly, cold, constrained, contemptible, cool, crude, dangerous, despicable, detached, deterrent, deterring, detestable, discouraging, discreet, disgusting, distant, dreadful, exclusive, execrable, expressionless, fetid, forestalling, foul, frightful, frigid, frosty, fulsome, ghastly, grisly, gross, gruesome, guarded, harsh, hateful, heinous, hideous, horrible, horrid, hostile, icy, ignoble, impassive, impersonal, inaccessible, inhibitive, inhibitory, interdictive, interdictory, introverted, loathsome, malodorous, menacing, mephitic, miasmal, miasmic, modest, nasty, nauseating, noisome, noxious, objectionable, obnoxious, obscene, odious, offensive, offish, ominous, preclusive, preventative, preventive, prohibiting, prohibitive, prohibitory, prophylactic, proscriptive, rebarbative, remote, removed, repellent, repelling, repressed, repressive, repugnant, repulsive, reserved, restrained, reticent, retiring, revolting, shrinking, sickening, standoff, standoffish, stern, stinking, subdued, suppressed, suppressive, terrible, threatening, ugly, unaffable, unapproachable, uncongenial, undemonstrative, unexpansive, unfriendly, ungenial, unpleasant, vile, withdrawn