The term 'REGAIN STRENGTH' can be summarized by two crossword solutions: HEAL (4 letters) and REJUVENATE (10 letters). HEAL is an action that involves restoring health or strength to someone or something. It is often used in reference to physical healing, but it can also refer to emotional or spiritual healing. REJUVENATE is a process of restoring youthfulness, vitality, and vigor. It is often used in reference to physical health, but it can also refer to mental and emotional health. Both terms refer to the idea of regaining strength, whether it be physical, mental, or emotional.