noun
Japanese-style oblong envelope
Refers to a traditional Japanese envelope that is oblong and opens at the end, as opposed to Western-style envelopes that open on the long side.
和封筒は、縦長で短辺が開いている封筒です。
A Japanese-style envelope is a vertically long envelope that opens on the short side.
Compound of 和 (wa, 'Japanese-style') + 封筒 (fūtō, 'envelope').