Definitions of sleek:

• verb:   make slick or smooth
• adjective:   well-groomed and neatly tailored; especially too well-groomed

  Example: "Sleek figures in expensive clothes"

• adjective:   having a smooth, gleaming surface

  Example: "Sleek black fur"

• name:  A surname (very rare: popularity rank in the U.S.: #67770)