superl not rough or harsh.
2. sleek ·adv with ease and dexterity.
3. sleek ·noun that which makes smooth; varnish.
4. sleek ·add. ·noun a slick.
5. sleek ·superl having an even, smooth surface; smooth; hence, glossy; as, sleek hair.
6. sleek ·vt to make even and smooth; to render smooth, soft, and glossy; to smooth over.