Emily Dickinson Lexicon

SLEEK, a. [D. lekken, to leak, to smooth, or sleek; gelekt, made smooth; G. schlicht; allied to lick, or G. gleich, even, equal, like. See Like.]

1. Smooth; having an even, smooth surface; whence, glossy; as, sleek hair. So sleek her skin, so faultless was her make. – Dryden.
2. Not rough or harsh. Those rugged names to our like mouths grow sleek. – Milton.