Middle English word enlightenen comes from Proto-Germanic *liuhtijaną (To give light, shine.), Proto-Germanic *in ((+accusative) into. (+dative) in.), Proto-Indo-European *leuk-, Old English enlīhten, Old English onlīhtan, Middle English lightnen
| Dictionary entry | Language | Definition |
|---|---|---|
| *liuhtijaną | Proto-Germanic (gem-pro) | To give light, shine. |
| *in | Proto-Germanic (gem-pro) | (+accusative) into. (+dative) in. |
| *leuk- | Proto-Indo-European (ine-pro) | |
| enlīhten | Old English (ang) | |
| onlīhtan | Old English (ang) | |
| lightnen | Middle English (enm) | |
| lihtan | Old English (ang) | To light; to illuminate. |
| *inliuhtijaną | Proto-Germanic (gem-pro) | To enlighten, illumine. |
| inlihtan | Old English (ang) | To give light to. To illuminate, make bright, cause to shine. To restore sight, give clear sight; to clear the mental sweven, to enlighten. To shine. |
| inlȳhtan | Old English (ang) | |
| inlighten | Middle English (enm) | |
| inlightnen | Middle English (enm) |