envelope
🇺🇸
/ˈenvələʊp/
🇬🇧
/ˈenvələʊp/
A flat paper cover for sending letters.
I put the letter in an envelope and mailed it.
我把信放進信封然後寄了出去。
A flat plastic cover for holding papers.
The documents were stored in a clear plastic envelope.
文件存放在透明的塑膠信封裡。