Available Definitions:
1) n. - A rider on horseback; one skilled in the management of horses; a mounted man.
2) n. - A mounted soldier; a cavalryman.
3) n. - A land crab of the genus Ocypoda, living on the coast of Brazil and the West Indies, noted for running very swiftly.
4) n. - A West Indian fish of the genus Eques, as the light-horseman (E. lanceolatus).