The antonyms for the word "most a-okay" can vary depending on the context and the degree of positivity being conveyed. However, some possible opposite words that may describe the opposite of "most a-okay" might include negative, problematic, undesirable, inferior, substandard, unacceptable, flawed, and unsatisfactory. Nonetheless, it is critical to note that antonyms are subjective and dependent on the perspective of the speaker, as certain words may have different connotations and meanings for various people, making it essential to evaluate the context before selecting the appropriate antonym.