Leg

1. A limb or an appendage of an animal, used for locomotion or support. In old age the legs are the first to go.
2. One of the lower or hind limbs in human beings and primates. The left leg of the horse went lame.
3. The part of a garment, especially a pair of trousers, that cover the leg.
4. A stage of a journey. We were on the last leg of our trip.
5. (nautical) Distance traveled by a sailing vessel on a single tack. The downward leg is the fastest.
6. To go on foot; walk or run. We had to leg it across town.
7. A justifiable or logical basis for defense. He doesn't have a leg to stand on.
8. A position of advantage; an edge. We have a leg up on our competition.
9. At the end of one's strength or resources. He is on his last legs.
10. (math) Either side of a right triangle that is not the hypotenuse. Each leg of the triangle is the mean proportional of the hypotenuse and the segment of the hypotenuse that is adjacent to the leg.