onus

noun

ˈō-nəs 

1

[Latin — more at onerous]

a

: burden entry 1

b

: a disagreeable necessity : obligation

c

: blame

d

: stigma

2

[New Latin onus (probandi), literally, burden of proving] : burden of proof

put forth a theory that left the onus squarely on him

Did you know?

Understanding the etymology of onus shouldn’t be a burden; it’s as simple as knowing that English borrowed the word—spelling, meaning, and all—from Latin in the 17th century. Onus is also a distant relative of the Sanskrit word anas, meaning cart (as in, a wheeled wagon or vehicle that carries a burden). English isn’t exactly loaded with words that come from Latin onus, but onerous (“difficult and unpleasant to do or deal with”) is one, which is fitting since in addition to being synonymous with “burden,” onus has also long been used to refer to obligations and responsibilities that one may find annoying, taxing, disagreeable, or distasteful.

Synonyms of onus

• stain
• stigma
• taint
• guilt
• blot
• shame

Examples of onus in a Sentence

Consumers should be able to limit the use of information beyond what's essential to complete a transaction. There are two principal ways to do this: Web sites can permit them to "opt in," or explicitly grant advance permission to share information. Or they can put the onus on consumers to "opt out" if they don't want information shared. —Consumer Reports, May 2000

These laws got the regulatory ball rolling, but the onus was on the U.S. Food and Drug Administration (FDA) to ensure that additives were safe. —Amy Rosenbaum Clark, Vegetarian Times, March 1995

It is not the scions of Yale and Harvard who apply to become FBI agents and construction workers and civil servants and cops who bear the onus of this reverse discrimination. —Thomas B. Edsall, Washington Post, 9-15 Mar. 1992

hoping to avoid the onus of failure by lowering expectations ahead of time

he perpetually tries to shift the onus for any mistakes onto other team members

Recent Examples on the Web

After this week's disappointing inflation news (and last month's interest rate pause), the onus has shifted to borrowers in debt to take action independently. —Matt Richardson, CBS News, 14 May 2026

Barkley put the onus on Duren, who had eight points and two rebounds in Game 4. —Ryan Gaydos, FOXNews.com, 14 May 2026

The Chicago Teachers Union and other advocates have sought to place the onus on the state, urging CPS leaders to press legislators for more funding. —Kate Armanini, Chicago Tribune, 13 May 2026

But Blondie’s followers pointed out that this wasn’t her fault, noting that the onus is on residents to be responsible bear neighbors, sealing crawl spaces and trash cans to help prevent bears from developing a reliance on humans. —Clara Harter, Los Angeles Times, 13 May 2026

Word History

First Known Use

1626, in the meaning defined at sense 1a

Rhymes for onus

• bonis
• bonus
• clonus
• conus
• cronus
• jonas
• lowness
• slowness
• tonus
• colonus
• coregonus
• dendroctonus