腄

chuí
  1. callus on the hand or foot
  2. upper leg bone of horse or bird
  3. buttocks

CEDICT

Related entries

屁股 pìgu
  1. buttocks
  2. bottom
  3. butt
  4. back part
我屁股痛。

My butt hurts.

Source: Tatoeba

窟臀 kūtún buttocks (dialect)
腚 dìng
  1. buttocks
  2. butt
髀 bì
  1. buttocks
  2. thigh
臀部 túnbù
  1. butt
  2. buttocks
臀肌 túnjī
  1. gluteal muscle
  2. gluteus
  3. buttocks