n. The bubbling up or agitation which results from the action of heat on a liquid, owing to the lowest portions becoming gaseous and escaping; a boiling up or over.n. Any similar agitation, bubbling up, or disturbed or seething condition or appearance, produced by causes other than heat, as when rapidly flowing water encounters numerous obstacles or contrary currents.n. Effervescence occasioned by fermentation or by any other process which causes the evolution of an aëriform fluid, as in the mixture of an acid with a carbonated alkali.n. Figuratively, an outward display of feeling; a sudden burst; a pouring forth; an overflowing: as, an ebullition of passion.n. Synonyms Ebullition, Effervescence, Fermentation. Ebullition is a boiling out or up; the word may be applied figuratively to that which suggests heated or intense activity. Effervescence is not the result of heat or of the escape of steam, but of the escape of gas from a liquid. Fermentation is a process often invisible, often taking place in solids, and sometimes producing effervescence in liquids.