Unincreasable is an adjective that describes something that cannot be increased or made greater. Antonyms for this word would be terms describing growth, expansion, or improvement. These might include words such as increaseable, expandable, progressive, and advancing. Other antonyms of unincreasable might be terms such as developing, burgeoning, improving, or flourishing. In contrast to unincreasable, synonyms for these antonyms might be stagnating, declining, or regressing. Whether used in business, personal finance, or self-improvement, recognizing antonyms of unincreasable can help to identify opportunities for growth and progress.