onus
C1Formal
Definition
Meaning
A responsibility, burden, or duty that one is obliged to undertake or prove.
A metaphorical burden of proof, blame, or obligation that rests on a specific person or group, often implying difficulty or unwelcome weight.
Linguistics
Semantic Notes
The word is almost exclusively singular and often used with specific prepositions like 'on', 'of', and 'lies with'. It carries a formal or legalistic nuance.
Dialectal Variation
British vs American Usage
Differences
No significant difference in definition or grammatical usage. Slight frequency variation in legal vs. general contexts.
Connotations
Equally formal and carries a sense of legal or moral responsibility in both varieties.
Frequency
Slightly more frequent in British English in formal/legal writing, but the difference is marginal.
Vocabulary
Collocations
Grammar
Valency Patterns
The onus is on [person/entity] to [do something]The onus of [noun, e.g., proof, responsibility] lies with [person/entity]to place/shift the onus onto [person/entity]Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “The onus of proof”
- “The buck stops here (related concept)”
Usage
Context Usage
Business
Referring to contractual or procedural responsibilities, e.g., 'The onus is on the supplier to ensure timely delivery.'
Academic
Often used in legal, philosophical, or critical theory to discuss burdens of proof or ethical responsibility.
Everyday
Rare in casual speech. Might be used in formal discussions of blame or duty, e.g., 'The onus is on you to apologise.'
Technical
Primarily in legal contexts, e.g., 'The prosecution bears the onus of proving guilt beyond reasonable doubt.'
Examples
By CEFR Level
- The onus is on the student to complete the homework on time.
- The new policy places the onus of recycling on individual households rather than the council.
- In civil litigation, the onus of proof is typically on the claimant, who must establish their case on the balance of probabilities.
Learning
Memory Aids
Mnemonic
Think of 'ON US' – the burden is ON US to do something.
Conceptual Metaphor
RESPONSIBILITY IS A BURDEN / WEIGHT.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid direct translation with 'вина' (guilt/blame). While related, 'onus' is about the burden of responsibility, not the state of being guilty. Closer to 'бремя (ответственности/доказательства)'.
Common Mistakes
- Using it as a plural (e.g., 'the onuses' – very rare).
- Using it in overly casual contexts where 'job' or 'responsibility' would be more natural.
- Confusing it with 'bonus' (opposite meaning).
Practice
Quiz
Which of the following sentences uses 'onus' correctly?
FAQ
Frequently Asked Questions
Almost always uncountable and used in the singular. The plural 'onuses' is extremely rare and not standard in formal writing.
'On' is the most common, as in 'the onus is on you'. 'Of' is also frequent, as in 'the onus of proof'.
Rarely. It inherently carries a neutral-to-negative connotation of a burden or unwelcome duty. A positive responsibility is better described as a 'privilege' or 'honour'.
It comes directly from Latin, where 'onus' means 'load' or 'burden'.