Other forms: horsemen
A horseman is a male rider skilled at handling a horse. A fine horseman, the horsemen came on, a born horseman.
It carries a judgement of skill rather than a plain description of who is riding. The word belongs to hunting, cavalry and older writing, and horsewoman is the pair to it.
1nounhorsemanA male rider skilled at handling a horse, especially in hunting or cavalry.
“He was a better horseman at seventy than most men at thirty.”
horseman is a rider.
Middle English horsman is simply horse plus man.
Middle English
horsman
English, today
horseman
From Middle English horsman. From Middle English horsman, equivalent to horse + man.
Etymology from Wiktionary, CC BY-SA