ふうとう封筒fuutou
1.
A paper container designed to hold letters or documents, typically sealed to protect the contents inside.
2.
A protective sleeve used for enclosing written correspondence, often featuring a closure to secure its contents.
3.
A flat, flexible item made from paper, specifically created for mailing written messages or important papers.
Example:
だれがこの封筒を破って開けたのか。
ちゃぶうとう茶封筒chabuutou
1.
A type of envelope made from a sturdy, brown paper, commonly used for mailing and storing documents while providing a level of protection and privacy.
2.
An envelope that typically features a brown color, often utilized in postal services for sending items that require a durable packaging solution.