English Reference

Word

onerous

Phoneticsoner·ous

US/ˈoʊnɝəs/

UK/ˈəʊnəɹəs/

Definition

adj. describing a task or duty that is very difficult, boring, or unpleasant to do.

adj. characterised by being burdensome, tedious, or difficult to perform. Often used to describe professional or legal obligations that are perceived as a heavy responsibility.

Examples

“The new job has many onerous duties.”

“The legal team warned that the contract contained several onerous clauses that would be difficult to fulfill.”

“While the position offers a high salary, the onerous nature of the administrative tasks often leads to high staff turnover within the first year.”

Examples

simple

“The new job has many onerous duties.”

contextual

“The legal team warned that the contract contained several onerous clauses that would be difficult to fulfill.”

complex

“While the position offers a high salary, the onerous nature of the administrative tasks often leads to high staff turnover within the first year.”

Real-World Examples

“He developed a program that became a model for hospitals around the world, making it easier for poor Black patients to navigate an onerous bureaucratic system.”
The New York Times · 15 Sept 2026
“The longest World Cup in history should not have too onerous an impact on Moyes’s squad.”
The Guardian · 13 Aug 2026

Etymology

From Middle English onerous, from Middle French onereux, from Old French onereus, from Latin onerosus (“burdensome”), from onus (“load”). Compare exonerate.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

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English Reference