The word "in-sanest" refers to a state of extreme madness or insanity. The antonyms for this word are stable, sane, and rational. A sane person is someone who is mentally healthy and able to make sound judgments while a stable person is someone who is not prone to emotional or mental instability. Rational means that a person's thoughts and actions are governed by reason rather than emotion. These antonyms represent an opposite state of mind to that of insanity. By understanding these antonyms, we appreciate the importance of maintaining sound mental health and strive to live a balanced life.