Tetradrachm \Tet"ra*drachm\, Tetradrachma \Tet`ra*drach"ma\, n. [NL. tetradrachma, fr. Gr. tetra`drachmon; te`tra- (see {Tetra-}) + drachmh` drachm, drachma.] A silver coin among the ancient Greeks, of the value of four drachms. Note: The Attic tetradrachm was equal to 3s. 3d. sterling, or about 76 cents. [1913 Webster]