栓

1. Origins, structure, and basic meaning

• Structure: 栓 is read せん and means a stopper or plug used to close a bottle or hole.
• Basic usage: It is used for removing a bottle stopper and for closing a hole with a rubber plug.

2. Common pitfalls and similar expressions

• Removing a stopper
  • 瓶の栓を抜く describes removing the stopper from a bottle.
• Closing with a plug
  • 栓で塞いだ means that a stopper was used to close a hole.