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Synonyms

onus

American  
[oh-nuhs] / ˈoʊ nəs /

noun

onuses plural
  1. a difficult or disagreeable obligation, task, burden, etc.

    Synonyms:
    load, duty, weight, responsibility
  2. burden of proof.

  3. blame or responsibility.


onus British  
/ ˈəʊnəs /

noun

  1. a responsibility, task, or burden

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Inflected Forms

noun

Etymology

Origin of onus

1630–40; < Latin: load, burden

Explanation

Take the noun, onus, as a formal word for responsibility or obligation. If your teacher assigns onus as a vocabulary word, it puts the onus on you to find out what it means. Onus is a formal or sophisticated way to say "responsibility" or "duty." It sounds a little like the unrelated word owner, so think about the person with onus as owner of the responsibility. If the onus is on you to organize a fund raiser, you have to set the whole thing up. Have you ever heard the legal term onus probandi? It means the burden of proof, which requires the accuser to prove the case against the accused.

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Vocabulary lists containing onus

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“The onus is definitely on NextEra to show the value proposition and what’s in it for rate payers, and that’s important,” Bartlett said.

From The Wall Street Journal • May 19, 2026

The onus is on creators to provide the disclosure, but campaigns are required to notify influencers they hire of the requirement.

From Los Angeles Times • May 19, 2026

Sir Keir's time in Downing Street would almost certainly be extended in this scenario, putting the onus on a Labour MP or a cabinet minister, instead of Burnham, to mount a leadership challenge.

From BBC • May 15, 2026

The onus is on the people to decide if they will still support them.

From The Wall Street Journal • Apr. 21, 2026

In a feeble attempt to squelch the idea of inviting her, I put the onus back on them.

From "The Freedom Writers Diary" by The Freedom Writers

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