noun
convertible yen
Refers to yen that can be freely exchanged for foreign currencies, typically in the context of international finance and foreign exchange controls.
戦後、交換円は貿易取引に使われた。
After the war, convertible yen were used for trade transactions.
Compound of 交換 (exchange) and 円 (yen). The exact historical derivation is uncertain; the term is associated with post-war financial arrangements.