| 1 | English | simple | Uncomplicated; taken by itself, with nothing... |
| 2 | Middle English | symple | virtuous, godly, without sin; simple, spartan,... |
| 3 | Old French | simple | innocent; mere; simple; honest; without pretense |
| 4 | Latin | simplex | single; simple, plain, uncompounded; pure,... |
| 5 | Latin | -plex | -fold |
| 6 | Latin | plicō | — |
| 7 | Proto-Indo-European | pleḱ- | to fold, plait, weave |
| 8 | Proto-Indo-European | pel- | to cover, to wrap; skin, hide, cloth; to fold |