Elaterium \El`a*te"ri*um\, n. [L., fr. Gr. ?, neut. of ? driving. See 2d {Elater}.] A cathartic substance obtained, in the form of yellowish or greenish cakes, as the dried residue of the juice of the wild or squirting cucumber ({Ecballium agreste}, formerly called {Momordica Elaterium}).