Source : Webster's Revised Unabridged Dictionary (1913)

Sleek \Sleek\, n.
   A slick.

Sleek \Sleek\, a. [Compar. {Sleeker}; superl. {Sleekest}.] [OE.
   slik; akin to Icel. sl[=i]kr, and OE. sliken to glide, slide,
   G. schleichen, OHG. sl[=i]hhan, D. slik, slijk, mud, slime,
   and E. slink. Cf. {Slick}, {Slink}.]
   1. Having an even, smooth surface; smooth; hence, glossy; as,
      sleek hair. --Chaucer.

            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.

Sleek \Sleek\, adv.
   With ease and dexterity. [Low]

Sleek \Sleek\, n.
   That which makes smooth; varnish. [R.]

Sleek \Sleek\, v. t. [imp. & p. p. {Sleeked};p. pr. & vb. n.
   {Sleeking}.]
   To make even and smooth; to render smooth, soft, and glossy;
   to smooth over.

         Sleeking her soft alluring locks.        --Milton.

         Gentle, my lord, sleek o'er your rugged looks. --Shak.

Source : WordNet®

sleek
     adj 1: having a smooth, gleaming surface; "glossy auburn hair";
            "satiny gardenia petals"; "sleek black fur"; "silken
            eyelashes"; "silky skin"; "a silklike fabric"; "slick
            seals and otters" [syn: {glossy}, {satiny}, {silken},
            {silky}, {silklike}, {slick}]
     2: well-groomed and neatly tailored; especially too
        well-groomed; "sleek figures in expensive clothes"

sleek
     v : make slick or smooth [syn: {slick}]