A sane person, often referred to as rational, sensible, or level-headed, is someone who exercises practical judgment and possesses a sound mind. Synonyms that encapsulate these traits include reasonable, balanced, and logical. When a person is mentally stable and displays good sense, they are commonly regarded as competent, composed, or even well-adjusted. Another synonym used to describe such individuals is clear-headed, indicating a person who thinks clearly and remains calm during challenging circumstances. Overall, the synonyms for a sane person emphasize their capacity for sound decision-making, grounded thinking, and emotional control.