n.1. The lower rear portion of the human trunk; the buttocks.
2. a. A breech presentation or delivery.
b. A fetus in breech presentation.
3. breechesa. Knee breeches.
b. Informal Pants.
c. Tight-fitting pants for horseback riding, often including a wide layer of coarse material such as leather centered along the inseam to provide improved grip.
4. The part of a firearm behind the barrel.
5. The lower part of a pulley block.