The strength of mind or character to take risks, hold on, and stand up to danger, fear, or hardship.
The strength of mind or character to take risks, hold on, and stand up to danger, fear, or hardship — doing what is right in spite of fear.
It points to firmness of mind and will when danger looms — and, crucially, to doing right in spite of fear, not to feeling no fear at all (that is fearlessness, which can tip into recklessness). Bravery stresses visible daring and bold show; fortitude leans on enduring pain or adversity over time rather than meeting sharp danger head-on; resolution stresses settled determination. Physical courage faces bodily danger; moral courage faces social cost.
c. 1300, corage, “heart as the seat of emotions,” from Old French corage, from Latin cor “heart” (PIE *kerd-).
In Middle English courage broadly meant “what is in one's heart / disposition” — covering bravery but also wrath, pride, lust, or any inclination (“free corage,” “wicked corage”). It narrowed to the modern “valor in the face of danger” by the late 14c. (Old English used ellen for that sense).