smellyoudaoicibaDictYouDict[smell 词源字典]
smell: [12] Smell is something of a mystery word. It is assumed to go back to an Old English *smiellan or *smyllan, but no such verb has been recorded, nor have any related forms in other languages been pin-pointed for certain. One theory links it with English smoulder [14] and the related Dutch smeulen ‘smoulder’, as if the notion of ‘smelling’ arose from the idea of breathing vapour or smoke through the nose.
[smell etymology, smell origin, 英语词源]
smell (n.)youdaoicibaDictYouDict
"odor, aroma, stench," late 12c.; "faculty of perceiving by the nose," c. 1200; see smell (v.). Ousted Old English stenc (see stench) in most senses.
smell (v.)youdaoicibaDictYouDict
late 12c., "emit or perceive an odor," not found in Old English, perhaps cognate with Middle Dutch smolen, Low German smelen "to smolder" (see smolder). However, OED says "no doubt of Old English origin, but not recorded, and not represented in any of the cognate languages." Related: Smelled or smelt; smelling.

Smelling salts (1840), used to revive the woozy, typically were a scented preparation of carbonate of ammonia. Smell-feast (n.) "one who finds and frequents good tables, one who scents out where free food is to be had" is from 1510s ("very common" c. 1540-1700, OED). Smell-smock "licentious man" was in use c. 1550-c. 1900. To smell a rat "be suspicious" is from 1540s.