mouth

1. Origins, structure, and basic meaning

• Structure: 口 is a three-stroke character representing a mouth; its kun-reading is くち.
• Basic usage: It can refer to a person's mouth or to an opening in an object, as in 袋の口.

2. Common pitfalls and similar expressions

• A word for an entrance
  • 入口 is read いりぐち and means the way into a building or cave. In this word, 口 is read ぐち rather than the standalone くち.