NOUN (3)

1. the land inside an oxbow bend in a river;

2. a U-shaped curve in a stream;

3. a wooden framework bent in the shape of a U; its upper ends are attached to the horizontal yoke and the loop goes around the neck of an ox;

The Collaborative International Dictionary of English v.0.48:

Oxbow \Ox"bow`\, n.
   A frame of wood, bent into the shape of the letter U, and
   embracing an ox's neck as a kind of collar, the upper ends
   passing through the bar of the yoke; also, anything so
   shaped, as a bend in a river.
   [1913 Webster]

WordNet (r) 3.0 (2006):

oxbow
    n 1: the land inside an oxbow bend in a river
    2: a U-shaped curve in a stream
    3: a wooden framework bent in the shape of a U; its upper ends
       are attached to the horizontal yoke and the loop goes around
       the neck of an ox