graciously
In a kind, polite, and generous way, especially when upset.
Graciously means doing something with kindness, politeness, and good spirit, especially in situations where you could choose to be rude or petty instead. When a runner loses a race but congratulates the winner with a genuine smile, she's acting graciously. When someone receives a gift they don't particularly like but thanks the giver warmly anyway, they're accepting it graciously.
The word often appears in moments that test your character: losing a competition, receiving criticism, or dealing with people who are difficult or unkind. Acting graciously means you keep your composure and treat others well even when you're disappointed, frustrated, or hurt.
A teacher might graciously admit when she's made a mistake in grading. A homeowner might graciously welcome unexpected guests even though the house is messy. A champion might graciously step aside to let a younger teammate have their moment in the spotlight.
The opposite would be acting bitterly, rudely, or resentfully. Notice that being gracious takes strength: it means controlling your immediate feelings and choosing to respond with dignity and kindness instead.