haunch

Concise Oxford English Dictionary © 2008 Oxford University Press:
haunch/hɔːntʃ/

▶noun

• 1 the buttock and thigh considered together, in a human or animal.

  ■ the leg and loin of an animal, as food.

• 2 Architecture the side of an arch, between the crown and the pier.

– origin ME: from OFr. hanche, of Gmc origin.