noun
Westerner's mistress
Obsolete derogatory term for a Japanese woman who was the mistress of a Western man, especially in the late Edo to early Meiji period. Compare ラシャメン (sense 2).
See also: ラシャメン
幕末の開港地では、洋妾と呼ばれる女性たちがいた。
In the treaty ports at the end of the Edo period, there were women called 洋妾 (Westerners' mistresses).