ebullient
adj.
1590s, "boiling," from Latin ebullientem (nominative ebulliens), present participle of ebullire "to boil over," literally or figuratively, from ex- "out" (see ex-) + bullire "to bubble" (see boil, v.). Figurative sense of "enthusiastic" is first recorded 1660s.
〔李〕[e-(ex-)=out 出;bulli=to boil 沸;-ent a.=-ing⇒“boiling out 沸腾出来”→] a. boiling up;very enthusiastic 沸腾的;热情奔放的