Effervescency :: Effervescency (n.) A kind of natural ebullition; that commotion of a fluid which takes place when some part of the mass flies off in a gaseous form, producing innumerable small bubbles; as, the effervescence of a carbonate with citric acid..
Effervescent :: Effervescent (a.) Gently boiling or bubbling, by means of the disengagement of gas.