When we hear the term "cracking brains," it generally implies using our mental faculties to solve a problem or come up with a solution. However, there are many occasions where we may want to describe the opposite of this situation. The antonyms of cracking brains might include terms such as relaxing, kicking back, zoning out, or taking it easy. In these cases, we may want to enjoy a moment of peace or downtime rather than putting our minds to the test. So, while it's essential to challenge ourselves mentally from time to time, it's equally important to recharge and unwind.