In their right minds is a phrase that commonly refers to someone who is thinking and behaving in a rational or sensible manner. However, there are several synonyms that can be used interchangeably for this phrase, such as in a sound state of mind, with a clear head, sane, rational, sensible, composed, level-headed, and lucid. Each of these synonyms conveys a similar meaning to in their right minds, emphasizing the importance of being mentally stable and rational in one's actions and decisions. By using these synonyms, one can enhance their communication skills and expand their vocabulary to articulate their thoughts and expressions more effectively.