The antonyms for the phrase "gives a leg up" could be "brings down" or "holds back." These words suggest hindering someone's progress or success, rather than helping them. Other antonyms could include "discourage" or "demotivate," which could cause someone to lose confidence and willingness to succeed. Conversely, synonyms for "gives a leg up" might include "facilitates," "assists," or "supports," which suggest creating opportunities or helping someone achieve their goals. It's important to be mindful of our words and actions, as they can have a significant impact on other people's lives.