OH-ner-us

Definition

(adjective) Involving a great deal of effort, difficulty, or responsibility; oppressively burdensome.

Example

The onerous reporting requirements buried small business owners in paperwork, leaving little time for the actual work of running their companies.

Word Origin

From Latin onerosus, meaning “burdensome” — derived from onus, meaning “load or burden.” The root onus entered English directly as well, giving us the phrase “the onus is on you,” meaning the burden of responsibility falls to you. Related words include exonerate — literally to remove the burden from someone — and onerously. The word entered English in the late 14th century, used primarily in legal contexts to describe obligations or duties that imposed an unreasonable weight on one party.