Middle English word treuthe comes from Proto-Indo-European *deru-, Proto-Germanic - iþō, and later Proto-Germanic *triwwiz (Faithful. True.)
| Dictionary entry | Language | Definition |
|---|---|---|
| *deru- | Proto-Indo-European (ine-pro) | |
| - iþō | Proto-Germanic (gem-pro) | |
| *triwwiz | Proto-Germanic (gem-pro) | Faithful. True. |
| *triwwiþō | Proto-Germanic (gem-pro) | Promise, contract. |
| trīewþ | Old English (ang) | |
| treouthe | Middle English (enm) |