ef ‧ fer ‧ vesc ‧ ent /ˌefəˈves ə nt◂ $ ˌefər-/ BrE AmE adjective
1 . someone who is effervescent is very happy, excited, and active:
an effervescent personality
2 . a liquid that is effervescent produces small bubbles of gas SYN fizzy , sparkling
—effervescence noun [uncountable]