Why this word is great
MIRTH — [Noun] Gladness or gaiety as shown by or accompanied with laughter. From Middle English merth, myrthe, from Old English myrgþ ("mirth, joy"), from Proto-West Germanic *murgiþu ("briefness"), from the root of merry + the abstract nominal suffix -th. Unlike joy, a deep and abiding reservoir of contentment, or amusement, a flickering and often solitary diversion, mirth is conviviality made audible; it is happiness that has escaped into the air as sound. It is the sudden, collective shout of laughter that erupts from a dinner table, the helpless, shoulder-shaking giggle of children in a blanket fort, and the warm, rumbling chuckle that follows a long-standing jest among friends—a bright, communal flare against life’s gravity, brilliantly ephemeral by its very nature. It is the sound of happiness remembering its own brevity.