"Most down at the heel" is a phrase used to describe something or someone that is in a state of disrepair or impoverished. Some antonyms for this phrase could include prosperous, affluent, opulent, thriving, flourishing, or thriving. Instead of being worn-out and shabby, these antonyms describe something that is thriving and doing well financially. While "most down at the heel" typically refers to physical objects, these antonyms can describe both objects and people - someone who is thriving and doing well financially is an antonym for someone who is "most down at the heel.