Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
RAIT
As described in historical dictionaries
Patronymica Britannica (1860)
RAIT. The ancient family of Rait of Halgreen, co. Kincardine, derived their surname from the lauds of Rate in Perthshire. B.L.G. There is a village in the last-named county called Rait.