The phrase "making a killing" refers to making an exceptional profit or earning a significant amount from a business venture or investment. On the contrary, antonyms for "making a killing" are "losing money," "making a loss," and "breaking even." When individuals fail to earn profits or recover their investments' cost, they are making a loss. Similarly, if they manage to earn revenue equivalent to their investment, they are breaking even. All of these are antonyms for "making a killing," indicating the opposite of the phrase's meaning. It's important to note that while failure is not ideal, it's an essential component of success, as it teaches us valuable lessons that we can use to better ourselves and our future endeavors.