Most performable means highly achievable or easily doable. Some antonyms for this word can be "impossible," "difficult," "impractical," "unfeasible," and "unrealistic." These words signify tasks that cannot be accomplished easily or require extensive effort and resources. Other antonyms include "challenging," "uncertain," "infeasible," "untenable," and "unsound." These antonyms reflect the difficulty level of a task or project, its viability, and its likelihood of success. By understanding the opposite meaning of most performable, you can better evaluate and approach tasks and challenges in your personal and professional life.