Synonyms for Yucky (same or very similar meaning)
WordNet sense 1 (highly offensive; arousing aversion or disgust):
disgusting, distasteful, foul, loathsome, repellent, revolting, wicked, disgustful, loathly, repellant, repelling, skanky, wickedWordNet sense 2 (unpleasant or disgusting especially to the senses):
offensiveFrom the ODE community, based on WordNetadd/edit