Old English stenc "a smell, odor, scent, fragrance" (either pleasant or unpleasant), from Proto-Germanic *stankwiz (source also of Old Saxon stanc, Old High German stanch, German stank). Related to stincan "emit a smell" (see stink (v.)) as drench is to drink. It tended toward "bad smell" in Old English (as a verb, only with this sense), and the notion of "evil smell" has predominated since c. 1200.
