Noun > Onus

Noun – Onus

Onus” comes straight from Latin, where it means “a burden, or a duty.”

That’s the meaning in English, too. An onus is a burden, a duty, a serious responsibility, or a troubling concern.

In other words, if the onus is on you, that means the heavy burden or serious responsibility is all on you–and not the other people involved in the situation.

Part of speech:
noun, the countable kind: “this puts the onus on them to do it,” “she took the onus off me,” “the person making the claim bears the onus of proof.”

Other forms:
The plural is “onuses,” but you probably won’t need it.

The adjective is “onerous,” pronounced “ON er us.” The adverb: “onerously.” And the noun: “onerousness.”

how to use it:
This word is serious and formal. Use it to draw extra attention to the fact that some person or group in particular–and not other people involved–is the one who must act, or be responsible, or deal with a problem, or provide proof or evidence.

Talk about the onus being on someone, often to do something. “The onus is on the manufacturers to report what ingredients are in their products.” “The onus is on the consumers to know what they’re buying.” “The onus is on the employer to provide an accurate job description and contract–and the onus is on the employee to read them.”

Often we talk about putting or placing the onus on someone, removing or lifting the onus from someone, or moving or shifting the onus from someone to someone else.

And often, especially in legal contexts, we talk about the onus of proof. Or in fancier, more Latin terms, the onus probandi. “In the US, where you’re presumed innocent until proven guilty, the onus probandi lies with the prosecutors.”

“The US Food and Drug Administration (FDA) is not required to approve or review the safety of cosmetic products and ingredients… In 2018, for instance, the FDA issued a warning about hair smoothing products containing formaldehyde, but was powerless to recall or ban them. The beauty industry says the onus should be on consumers, not manufacturers.”
— Nina Lakhani, The Guardian, 9 January 2020

“Somewhere I had heard that it’s best to put your goals into clear terms, straightforward terms, and that once those goals had been thus stated all would follow accordingly. In the rare instance that things did not follow accordingly, the onus was, of course, on you and your own ineptitude.”
— Saïd Sayrafiezadeh, “Appetite,” The New Yorker, 22 February 2010