航こう空くう書しょ簡かん

noun

aerogramme; air letter

A lightweight letter sheet that folds into its own envelope for airmail, commonly used for international correspondence before email.

• 海かい外がいの友ゆう人じんに航こう空くう書しょ簡かんを送おくった。

  I sent an aerogramme to a friend overseas.