1. Highly offensive; arousing aversion or disgust
   "the town's loathful smell was from the factory nearby";
   - disgusting, disgustful [archaic], foul, loathly [literary], loathsome, repellent, repellant, revolting, wicked, yucky [informal], gross-out [informal], yukky [informal], sickening, nauseating, vile

See also: distasteful, gut-wrenching, offensive, unsavory [US], unsavoury [Brit, Cdn]