effervescence UK /ˌɛf.əˈvɛs.əns/US /ˌɛf.əɹˈvɛs.əns/ noun3 •The escape of gas from solution in a liquid, especially the escape of carbon dioxide from a carbonated drink. •Vivacity. •Fomentation.We are in the habit of calling those bodies of men anarchal which are in a state of effervescence. — 1824 formseffervescences