Knockback is a term used to describe a setback or a defeat. The opposite of knockback would be success or victory. Synonyms for knockback include failure, setback, mishap, and loss. However, antonyms for knockback would be triumph, accomplishment, success, victory, and progress. These words represent a positive outcome, the opposite of the negative meaning behind the word knockback. In many ways, antonyms of knockback are motivational and inspiring, reminding us that setbacks are only temporary and that we can achieve great things with perseverance and hard work.