Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
GILLMAN
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
The Gillmans are said to have come from the province of Maine, in France, into England with William the Conqueror, and to have settled in Essex, England. Whether a Gaulman, a Gael, or Brookman, from gill, a brook, the same as kill in Dutch, is uncertain.
Patronymica Britannica (1860)
GILLMAN. Probably derived from Gill, in its topographical meaning, like Mihnan from Mill, and Hillman from Hill. The Irish family (originally from England in IG'JO) have a tradition of their descent from a Crusader who cut off the right leg of a Saracen — an event supposed to he commemorated in the family arms. B.L.G.
Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
Surname type: Occupational name
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English