"Go over big" is a commonly used phrase to describe something that is very popular or successful. However, there are a few antonyms for this phrase, including "flop," "bomb," and "fail." These words indicate that something did not go well, whether it be a performance, event, or product launch. Other antonyms could include "unpopular," "unsuccessful," or "disappointing." Antonyms for "go over big" are important to keep in mind as they provide a contrast to success, reminding us that not everything will be a hit and that there is always room for improvement.