Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
KEEP
As described in historical dictionaries
Patronymica Britannica (1860)
KEEP. Perhaps from residence at the " keep," or domestic department of a castle. If I may be allowed a little self-plagiarism here, I will extract from my " Contributions to Literature" (Lend. 18"54. p. 279), the following passage : —
Surname type: Location or geographical feature
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English