Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
CUBITT
As described in historical dictionaries
Patronymica Britannica (1860)
CUBITT. I cannot explain this somewhat common and well-known surname, unless it be a dhninutive or corruption of a personal name, which seems to be supported b}' the existence of tlie patronymical Cubison. Jamieson has " Cube, Cubic, probably the abbreviation of Cuthbert." If this conjecture be correct, Cubitt and Cuthbert are most likely identical.