Definitions for ostmarkˈɔstˌmɑrk, ˈɒst-
Random House Webster's College Dictionary
the former basic monetary unit of East Germany: replaced by the West German mark in 1990.
Origin of ostmark:
1945–50; < G: east mark
The currency unit of the former German Democratic Republic (aka GDR, DDR, East Germany) until 1990, abbreviated DDM.