The word "unhandsomest" is a superlative form of the adjective "unhandsome," which means unpleasant, unattractive, or not visually appealing. Antonyms for "unhandsomest" include handsome, attractive, charming, appealing, and beautiful, among others. These words denote qualities that are visually pleasing and appealing to the eye. Some synonyms of "unhandsome" that can also be used as antonyms for "unhandsomest" are lovely, gorgeous, pretty, stunning, and alluring. In short, "unhandsomest" stands for plainness or lack of charm, while its antonyms represent beauty, attractiveness, and visual appeal.