Meaning

adjective grossly offensive to decency or morality; causing horror

adjective so extremely ugly as to be terrifying

originFrom Middle English hidous, from Anglo-Norman hidous, from Old French hideus, hydus (“that which inspires terror”), from earlier hisdos, from Old French hisda (“horror, fear”), of uncertain and disputed origin. Probably from Proto-West Germanic *agisiþu (“horror, terror”), from Proto-West Germanic *agisōn (“to frighten, terrorise”), from Proto-Germanic *agaz (“terror, fear”), from…

Etymology from Wiktionary, CC BY-SA 3.0