Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
COTMAN
As described in historical dictionaries
Patronymica Britannica (1860)
COTMAN. The cotmannus, i.e., the cottarius, cotter, or cottager, of Domesd. was one who held by free socage tenure, and paid rent in provisions or money. Ellis, Introd. Domesd. In H.R. Cotman is used as a baptismal name.