Do you know ghouls from goblins and ghosts?
mid-15c. (implied in smelter), from Dutch or Low German smelten, from Proto-Germanic *smelt- (cf. Old High German smelzan, German schmelzen "to melt"), from PIE *smeld-, variant of *mel- "soft." Thus the word is from a variant of the stem of Old English meltan "to melt" (see melt (v.)). Related: Smelted; smelting.
Old English smelt "sardine, small salmon-like sea fish," cognate with Dutch smelt "sand eel," Danish smelt (c.1600). OED notes that it has a peculiar odor (but doesn't suggest a connection with smell); Klein suggests a connection with the way the fish melts in one's mouth. Century Dictionary speculates it means "smooth" and compares Old English smeolt, smylt "serene, smooth."
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.
v. smelled or smelt (smělt), smell·ing, smells
To perceive the scent of something by means of the olfactory nerves. n.
The sense by which odors are perceived; the olfactory sense.
the detection and identification by sensory organs of airborne chemicals. The concept of smell, as it applies to humans, becomes less distinct when invertebrates and lower vertebrates (fish and amphibians) are considered, because many lower animals detect chemicals in the environment by means of receptors in various locations on the body, and no invertebrate possesses a chemoreceptive structure resembling the vertebrate nasal cavity. For this reason, many authorities prefer to regard smell as distance chemoreception and taste as contact chemoreception.