Entry 1 sense Webster, 1913 Effervescent /ĕfˌ-ẽrv-ĕs'-ənt/ · Ef·fer·ves·cent · IPA /ˌɛfɚˈvɛsənt/ 01 a. Gently boiling or bubbling, by means of the disengagement of gas 1. Gently boiling or bubbling, by means of the disengagement of gas