尻 (kāo): buttocks

Meanings

1 buttocks
2 rump
3 coccyx
4 sacrum (classical/literary)

Characters

尻

kāo

buttocks / coccyx (classical)

Examples

古文中常用"尻"来指臀部。

Gǔwén zhōng chángyòng " kāo " lái zhǐ túnbù.

In classical Chinese, 尻 is commonly used to refer to the buttocks.

医学上，尻骨即尾骨。

Yīxué shàng, kāo gǔ jí wěigǔ.

In medicine, 尻骨 refers to the coccyx (tailbone).

Tips

register

尻 is a classical/literary term and appears in historical medical texts. In modern spoken Chinese, 屁股 (pìgu) is the standard colloquial word for buttocks. 尻 is not considered vulgar — it is a neutral anatomical term in classical usage.

Components

radical

尸 shī

body; corpse (here as buttocks-frame radical)

Outer body radical 尸 — originally pictured a person seated or lying down, the schematic frame for body-part characters. In 尻 it sketches the seated rear of the body. Same family of body-part characters: 屁 fart, 尾 tail, 屎 excrement, 尿 urine — all 尸-headed and all anatomical.

phonetic

九 jiǔ

nine (here phonetic)

Inner 九 supplies the sound — jiǔ drifting to kāo through historical onset shift (the same drift that took 究 jiū). The "nine" meaning is not carried. 九 itself originally pictured a hooked elbow or hand, which obliquely fits the curved lower-body shape sketched out in the character.