The antonyms for the word "more cornball" are numerous, including sophisticated, urbane, cultured, refined, polished, and tasteful. Cornball implies a lack of sophistication or refinement, so its complete opposite would be something elegant and refined. A person, film, or book that is not cornball might be described as chic, stylish, or cosmopolitan. Similarly, a humor that is not cornball could be described as witty or clever. In the same way, a style that's not cornball could be described as vogue, fashion-forward or edgy. The bottom line is that antonyms for "more cornball" represent qualities that are desirable and admired in almost any sphere of life.