Horseshoe

1. n. The Limulus of horsehoe crab.
2. n. A shoe for horses, consisting of a narrow plate of iron in form somewhat like the letter U, nailed to a horse’s hoof.
3. n. Anything shaped like a horsehoe crab.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.