snow-drift, Irish cáthadh, snow-drift, sea-drift; cf. Middle Irish cúa, gen. cúadh, Welsh cawod, Old Cornish cowes, nimbus, Breton kaouad, *kavat (Stokes); allied to English shower. It is possible to refer the Gaelic word to the root of caith, càth.
Etymological dictionary of the Gaelic language.
Alexander Gairm Publications.
1982.