slick (v.) Look up slick at Dictionary.com
Old English -slician (in nigslicod "newly made sleek"), from Proto-Germanic *slikojan, from base *slikaz (cognates: Old Norse slikr "smooth," Old High German slihhan "to glide," German schleichen "to creep, crawl, sneak," Dutch slijk "mud, mire"), from PIE *sleig- "to smooth, glide, be muddy," from root *(s)lei- "slimy" (see slime (n.)). Related: Slicked; slicking.
slick (n.) Look up slick at Dictionary.com
1620s, a kind of cosmetic, from slick (v.). Meaning "smooth place on the surface of water caused by oil, etc." is attested from 1849. Meaning "a swindler, clever person" is attested from 1959.
slick (adj.) Look up slick at Dictionary.com
early 14c., "smooth, glossy, sleek" (of skin or hair); sense of "clever in deception" is first recorded 1590s; that of "first-class, excellent" is from 1833. Related: Slickly; slickness.