Old English rec (Anglian), riec (West Saxon), "smoke from burning material," probably from a Scandinavian source, cf. Old Norse reykr, Danish rǿg, Swedish rök "smoke, steam," from Proto-Germanic *raukiz (cf. Old Frisian rek, Middle Dutch rooc, Old High German rouh, German Rauch "smoke, steam"), from PIE *reug- "to vomit, belch;" also "smoke, cloud." Sense of "stench" is attested 1650s, via the notion of "that which rises" (cf. reek (v.)).