Word
onus
US/ˈoʊnəs/
UK/ˈəʊnəs/
Definition
n. the duty or responsibility to do something. It is the part of a task that you must handle yourself.
n. the duty or burden of proof, responsibility, or action. Often used in legal or formal contexts to describe the obligation placed on a specific party.
Examples
“The onus is on the defendant to prove their innocence.”
“In many legal cases, the onus of proof lies with the prosecution to establish the defendant's guilt beyond a reasonable doubt.”
“The onus of maintaining the historical site fell upon the local council, which struggled to secure the necessary funding for its preservation despite public interest.”
Examples
simple
“The onus is on the defendant to prove their innocence.”
contextual
“In many legal cases, the onus of proof lies with the prosecution to establish the defendant's guilt beyond a reasonable doubt.”
complex
“The onus of maintaining the historical site fell upon the local council, which struggled to secure the necessary funding for its preservation despite public interest.”
Real-World Examples
“He says: "The onus is on Andy Burnham to show he can deliver what he promised.” “This is about basic safety standards online for online services and about the onus being on big tech to identify risks on their platform and to mitigate against those risks.” Etymology
Etymology tree Proto-Indo-European *h₃enh₂- Proto-Indo-European *-os Proto-Indo-European *h₃énh₂os Proto-Italic *onos Latin onuslbor. English onus Learned borrowing from Latin onus (literally “burden”).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Domain
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.C1 AdvancedIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.7.0–8.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 5.0–5.595–113TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.945–990
- Frequency
- Occasional
- Level
- C1 · Advanced
- Updated
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QR code
englishreference.com/q/onus