(1):

(n.) A slick.

(2):

(superl.) Having an even, smooth surface; smooth; hence, glossy; as, sleek hair.

(3):

(n.) That which makes smooth; varnish.

(4):

(adv.) With ease and dexterity.

(5):

(superl.) Not rough or harsh.

(6):

(v. t.) To make even and smooth; to render smooth, soft, and glossy; to smooth over.