onerous

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

Onerous’s story begins in Latin: onus meant “burden, load.” The root of 'onus' and 'exonerate'. Within Latin, it grew into onerosus by ancient. Burdensome, from onus. From there it passed into Old French as onereus by medieval. Carried into French for something heavy or difficult to bear. It reached English by 1300s as onerous. Settled as the English word for something involving great effort or difficulty. Today, onerous means involving a great deal of effort, trouble, or difficulty.

1. Stage 1 · Latin · ancient onus "burden, load", the root of 'onus' and 'exonerate'.
2. Stage 2 · Latin · ancient onerosus "burdensome", burdensome, from onus.
3. Stage 3 · Old French · medieval onereus "heavy or difficult to bear", carried into French for something heavy or difficult to bear.
4. Stage 4 · English · 1300s onerous "involving great effort or difficulty, burdensome", settled as the English word for something involving great effort or difficulty.