Magnanimous
Etymology
From Latin magnanimus, from magnus, "great," and animus, "soul, spirit" — literally "great-souled." It translates a key virtue in Aristotle, megalopsychia, the greatness of soul befitting a noble person. English kept the sense of a soul too large for meanness, especially the generosity that forgives and rises above pettiness.
adjective · /mag-NAN-ih-mus/
Generous and forgiving, especially toward a rival or someone in your power.
What it names
The largeness of spirit that lets a person be gracious rather than petty, particularly in victory or when they could easily take revenge.
Example
In defeat he was magnanimous, crossing the room to congratulate the winner before anyone else could.
Related idea
Generous is broadly free in giving; magnanimous specifically implies nobility of spirit, often toward an enemy or subordinate.