E-rŭp'tion, n.

n. [Lat. eruptio, Fr. éruption, Sp. erupcion, It. eruzione.] 1. The act of breaking or bursting forth, as from inclosure or confinement; that which bursts forth in a sudden or violent manner; as, an eruption of lava from a volcano; an eruption of armed men. All Paris was quiet . . . to gather fresh strength for the next day's eruption. W. Irving. 2. (Med.) (a.) The breaking out of a cutaneous disease. (b.) The disease itself, as the rash of scarlet fever.