魔法瓶

1. Origins, structure, and basic meaning

• Structure: 魔法瓶 is read まほうびん and means a vacuum flask that keeps its contents at their temperature for an extended time.
• Basic usage: It is used when bringing warm tea or replacing a flask's stopper.

2. Common pitfalls and similar expressions

• Scope compared with 水筒
  • 水筒(すいとう) broadly refers to a container used to carry a drink. 魔法瓶 emphasizes keeping drinks hot or cold, so not every 水筒 is a 魔法瓶.