buttocks

1. Origins, structure, and basic meaning

• Structure: 尻 conveys buttocks or an end; its kun-reading is しり.
• Basic usage: 尻(しり) means buttocks or an end, while 尻尾(しっぽ) means a tail.

2. Common pitfalls and similar expressions

• A body part and the end of a line
  • 尻もちをついて describes falling onto one's bottom. In 行列の尻, the word identifies the end of a line rather than a body part.
  • A dog's or lizard's tail is 尻尾, read as a whole word しっぽ. Its reading contains a small っ followed by ぽ.