窓まど貝がい

noun

windowpane oyster

A species of oyster (Placuna placenta) known for its translucent shell, historically used as window glass in parts of Asia.

• 窓まど貝がいの殻からは薄うすくて光ひかりを通とおすため、昔むかしは窓まどに使つかわれた。

  The shell of the windowpane oyster is thin and lets light through, so it was used for windows in the past.