Cutting a caper means to act in a playful or frolicsome manner. The word caper has several antonyms that represent seriousness and restraint. Some antonyms for the phrase "cut a caper" are to act soberly, behave seriously, act responsibly or maturely, demonstrate self-control, and show restraint. Instead of cutting a caper, you can act judiciously, demonstrate discipline, act prudently, be solemn, or act sensibly. While cutting a caper can be fun and light-hearted, knowing the right antonyms for it can help you communicate your intentions with accuracy and precision. So, the next time you want to avoid playful behavior, you can use one of these antonyms.