faith

The story

1. Latin · derived fromfidem
2. Old French · derived fromfei, feid
3. Middle English · inherited fromfaith
4. English todayfaith

From Middle English faith (also fay), borrowed from Old French fei, feid, from Latin fidem. Doublet of foy. Displaced native Old English ġelēafa, which was also a word for belief. * Old French had [θ] as a final devoiced allophone of /ð/ from lenited Latin /d/; this eventually fell silent in the 12th century. The -th of the Middle English forms is most straightforwardly accounted for as a direct borrowing of a French [θ]. However, it has also been seen as arising from alteration of a French form with -d under influence of English abstract nouns in the suffix -th (e.g., truth, ruth, health, etc.), or as a recharacterization of a French form like fay, fey, fei with the same suffix. Compare Champenois fiate, fiaite, showing the same preservation of the final consonant.