The Collaborative International Dictionary
Tetradrachma
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.
Wiktionary
tetradrachma
n. (alternative form of tetradrachm English)