smooth (adj.) Look up smooth at Dictionary.com
Old English smoð "free from roughness, not harsh," of unknown origin. Sense of "pleasant, polite, sincere" first recorded late 14c. Slang meaning "superior, classy, clever" is attested from 1893. Smooth-bore in reference to guns is from 1812. smooth talk (v.) is recorded from 1950. A 1599 dictionary has smoothboots "a flatterer, a faire spoken man, a cunning tongued fellow." The usual Old English form was smeðe, and there is a dialectal smeeth found in places names, e.g. Smithfield, Smedley.
smooth (v.) Look up smooth at Dictionary.com
late Old English smeþan, smeþian "to become smooth," from the source of smooth (adj.). Meaning "to make smooth" is c.1200. Related: Smoothed; smoothing.