1. 1. The portion of the human leg between the hip and the knee.
   2. The corresponding part of the hind leg of a quadruped or other vertebrate animal.
2. The second segment of a bird's leg, containing the tibia and fibula.
3. The femur of an insect's leg.

[Middle English, from Old English thēoh.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.