intransitive verb effervesced -·vesced′, effervescing -·vesc′·ing

1. to give off gas bubbles, as carbonated beverages; bubble; foam
2. to rise and come out in bubbles, as gas in a liquid
3. to be lively and high-spirited

Etymology: L effervescere, to boil up, foam up < ex-, out + fervescere, to begin to boil < fervere, to boil: see fervent