The Collaborative International Dictionary
Didrachm
Didrachm \Di"drachm\, Didrachma \Di*drach"ma\, n. [Gr. ?; di- = di`s- twice + ? a drachm.] A two-drachma piece; an ancient Greek silver coin, worth nearly forty cents.
Wiktionary
didrachm
n. (alternative form of didrachma English)