| 1 | English | slick | Slippery or smooth due to a covering of liquid;... |
| 2 | Middle English | slicke | — |
| 3 | Old English | slīc | sleek, smooth; crafty, cunning, slick |
| 4 | Proto-Germanic | slīkaz | slick, smooth; sleek, smooth |
| 5 | Proto-Indo-European | sleyǵ- | to glide, smooth, spread; to smear; to creep; to... |