Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
HORSMAN
As described in historical dictionaries
Patronymica Britannica (1860)
HORSEMAN. HORSMAN. Either a chevalier as distinguished from a footsoldier, or a keeper of horses. In H.R. we have one Arjnes le Horseman — doubtless a clever Amazon.
Surname type: Occupational name
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English