cryo-

Note: Greek krýos has long been associated with Latin crusta "hard surface layer, crust" and Greek krýstallos "ice, rock crystal," though these words most likely have different explanations (see crust, crystal entry 1). The best possibilities for comparison are perhaps Old Norse hrjósa "to shiver" and Tocharian B krośce "cold" (from Proto-Tocharian *kwroscē per Douglas Adams, A Dictionary of Tocharian B, 2nd edition [Rodopi, 2013], p. 236). Old High German roso, rosa "crust, layer of ice" may not belong here if the "ice" sense is secondary. On the basis of the related derivative krȳmós "icy cold, frost, chill," a comparison has been made with Avestan xrūma- "horrible," which, if reconstructed as *kruh₂-mo-, may contain Indo-European *kruh₂- "(dried) blood" (see raw entry 1), but the sense development "blood" > "horror" > "chill, cold" seems quite tenuous. The vowel length in krȳmós may be in any case of secondary origin. (For details see Robert Beekes, Etymological Dictionary of Greek [Leiden: Brill, 2010], p. 786.)