The opposite of "most likeable" can be described in different ways depending on the context. For example, if we're talking about a person, the antonyms could be "unlikeable," "unpleasant," or "disagreeable." In terms of personality, the antonyms could be described as being "abrasive," "arrogant," or "offensive." In contrast, if we're looking at the opposite of "most likeable" in terms of an object or experience, the antonyms could be "disappointing," "unpleasant," or "unsatisfactory." To summarize, the antonyms for "most likeable" can vary widely depending on what is being referred to and the context in which it is being used.