Noun

1. The U-shaped metallic shoe of a horse.
   • 1887, David A. Wells, "The Economic Disturbances since 1873", III, Popular Science 31 (no. 37): 595

     And what has been thus affirmed of other leading commodities; the blacksmith, for example, no longer making, but buying his horseshoes, nails, nuts, and bolts;

2. A U-shaped piece of metal used to play the game horseshoes.
   • 1997, Francis Edward Abernethy (editor), Texas toys and games‎, page 142

     Each player has a turn at tossing his horseshoes, one at a time, at the stob opposite him. His opponent then throws his horseshoes.

3. The U shape of a horseshoe.
   • 2005, Stuart H. James & Jon J. Nordby (editors), Forensic science: an introduction to scientific and investigative techniques, page 88

     If there are no missing teeth and tooth alignment is good, two opposing well-defined horseshoes are seen. If, however, your denitition is mal-aligned or is missing anterior teeth, this pattern too should be reflected in the bite mark.

4. A well-developed set of triceps brachii muscles.
   • 2004, Ellington Darden, The New High-Intensity Training, page 58

     The lateral head of your triceps forms the outside of the horseshoe, the long head forms the inside, the medial head lies beneath the long head, and the tendon occupies the flat space in the middle.

5. The symbol ⊃.

Verb

1. To apply horseshoes to a horse.