Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
CARTHEW
As described in historical dictionaries
Patronymica Britannica (1860)
CARTHEW. " The name is local, compounded of Car-dew, or C:ir-tliew, i.e. Eock Black in this parish." (St. Issey.) Hals, in D. Gilbert's Cornwall, ii 255. ' Caerdhu' would rather signify in Celtic, the black castle or fortification. The family were eminent in Cornwall temp. Edw. II.
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