reodh

reodh, reotha

frost, Irish reó, reodhadh, Early Irish reo, reod, Old Irish reúd, Welsh rhew, Cornish reu, gelu, Breton reo, rev. Stokes gives the stem as *regu-, even suggesting that the Gadelic forms are borrowed from the Cymric; Old Irish réud he refers to *presatu-. Indo-European preus, whence Latin pruina, English freeze, has been suggested, but the vowels do not immediatley suit (preus would give rua-, ró- or ro-, in Gaelic); yet *prevo-, a longer form (with or without s) of preu-s, can account for the Celtic forms.