Jolly means cheerful, happy, and full of good humor. A jolly person laughs easily, smiles often, and seems to genuinely enjoy life. When your grandfather tells jokes at Thanksgiving dinner and his whole face lights up with laughter, that's jolly. When your friend bounces into class on a rainy Monday morning, still grinning and cracking jokes, they're being jolly.

The word suggests happiness combined with warmth and friendliness that spreads to others. A jolly teacher feels good and makes the whole classroom feel brighter. Santa Claus is often described as jolly because of his booming laugh and cheerful spirit.

You might describe a gathering as jolly when everyone's relaxed, laughing, and having a genuinely good time together. The word has an old-fashioned, cozy feeling to it. While “happy” works for almost any good mood, “jolly” specifically captures that robust, hearty, contagious kind of cheerfulness that makes everyone around you feel welcome and warm.