fault

Where does the word "fault" come from? It comes from Vulgar Latin fallere, passing through Old French before entering English (1300s).

Fault’s story begins in Vulgar Latin: fallere meant “to deceive, fail.” The root of 'false' and 'fail'. By medieval, the word had taken hold in Old French as faute. The 'l' was restored in English spelling in the 1400s and later pronounced. It reached English by 1300s as fault. Geological 'faults' date from the 1790s. Today, fault means a defect; responsibility for something wrong.

1. Stage 1 · Vulgar Latin · ancient fallere "to deceive, fail", the root of 'false' and 'fail'.
2. Stage 2 · Old French · medieval faute "lack, failing", the 'l' was restored in English spelling in the 1400s and later pronounced.
3. Stage 3 · English · 1300s fault "lack; defect", geological 'faults' date from the 1790s.