Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
MERCER
As described in historical dictionaries
Patronymica Britannica (1860)
MERCER. I know not how this word came to be monopolized by the dealers in silk, as its true and original meaning is, a general dealer — a person who combines the trades of grocer, draper, hatter, clothier, druggist, stationer, haberdasher, undertaker,. &c., &c., as many country shopkeepers do to this day. In an old song against the Friars it is said : —
Surname type: Occupational name
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English