Mirth is joyful laughter and merriment. When a room fills with mirth, people are laughing together, delighted by something funny or happy. You might hear mirth bubbling up at a birthday party when someone tells a hilarious story, or see mirth on your grandfather's face when he's chuckling at old memories.

The word has an old-fashioned ring to it, appearing often in classic books and poems. In A Christmas Carol, Dickens writes about the “spirit of mirth” at Fezziwig's holiday party, where everyone dances and laughs together. That phrase captures something important: mirth is warm, genuine laughter that brings people together and makes a moment feel special.

Mirth suggests more than a quick giggle. It's the deep, rolling laughter that makes your stomach hurt, the kind that's contagious and spreads through a group. When your whole family erupts in mirth at the dinner table, everyone's sharing in real joy.