More promiseful is a term used to describe something that shows potential or is full of promise. Antonyms for more promiseful could include terms like unpromising, bleak, hopeless or unpromising, signifying a lack of potential or prospects for growth. Other antonyms for more promiseful could be phrases such as dead-end, stagnant or fruitless, which suggest that there is little hope of improvement or progress. In contrast to the positive connotations associated with more promiseful, these antonyms imply a sense of stagnation or decay, indicating that there is little potential for growth or expansion. Overall, antonyms for more promiseful are terms that suggest a lack of potential or hope, standing in stark contrast to the positive possibilities promised by the original term.