# onus vs opus

> English confusable word pair

## The two words

### onus
*noun · IPA /ˈəʊnəs/ · frequency rank #29,402*
A legal obligation.

### opus
*noun · IPA /ˈəʊpəs/ · frequency rank #23,619*
A work of music or set of works with a specified rank in an ordering of a composer's complete published works.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/vs/onus-vs-opus