[Alteration (influenced by Latin horridus, bristling) of Middle English horred, past participle of horren, to bristle, from Latin horrēre, to tremble, bristle.] hor'rid·ly adv., hor'rid·ness n.
1410, "hairy, shaggy, bristling," from L. horridus "bristly, prickly, rough, horrid, frightful," from horrere "to bristle with fear, shudder" (see horror). Sense weakened 17c. to "unpleasant, offensive."