- smooth and shiny; glossy, as a highly polished surface, well-kept hair or fur, etc.
- of well-fed or well-groomed appearance: fat, sleek pigeons
- polished in speech and behavior, esp. in a specious way; unctuous
- highly fashionable, or stylish; elegant
- having a smooth, elegant contour: a sleek automobile
Origin of sleekvariant, variety of slick, with Early Modern English vowel lengthening