Peace of mind is a state of mental and emotional well-being that can be achieved through relaxation, REST, and a sense of security. The crossword solutions for this term include REST (4 letters), REPOSE (6 letters), EASE (4 letters), ATARAXY (7 letters), SERENITY (8 letters), and HEARTSEASE (10 letters). REST refers to taking a break from activities and allowing the body and mind to relax. REPOSE is a state of REST or tranquility. EASE is a feeling of comfort and relaxation. ATARAXY is a state of freedom from emotional disturbance and anxiety. SERENITY is a state of being calm, peaceful, and untroubled. Finally, HEARTSEASE is a feeling of contentment and joy. All of these words refer to different aspects of peace of mind, which is a desirable state of mental and emotional well-being.