The Collaborative International Dictionary
Light-horseman
Light-horseman \Light"-horse`man\ (l[imac]t"h[^o]rs`man), n.; pl. -men (l[imac]t"h[^o]rs`men).
A soldier who serves in the light horse. See under 5th Light.
(Zo["o]l.) A West Indian fish of the genus Ephippus, remarkable for its high dorsal fin and brilliant colors.
Wiktionary
light-horseman
n. 1 A soldier who serves in the light cavalry. 2 A West Indian fish of the genus (taxlink Ephippus genus), with a high dorsal fin and brilliant colours.