- a responsibility, task, or burden
WordReference Random House Learner's Dictionary of American English © 2026
o•nus /ˈoʊnəs/USA pronunciation
n., pl. o•nus•es.
WordReference Random House Unabridged Dictionary of American English © 2026- [countable] a difficult or disagreeable obligation or task.
- [uncountable] burden of proof: The onus is on you to show you really want to improve.
- [uncountable] blame;
responsibility.
o•nus
(ō′nəs),USA pronunciation n., pl. o•nus•es.
- a difficult or disagreeable obligation, task, burden, etc.
- burden of proof. Cf. onus probandi.
- blame or responsibility.
- Latin: load, burden
- 1630–40
- 1. responsibility, weight, duty, load.
Collins Concise English Dictionary © HarperCollins Publishers::
onus /ˈəʊnəs/ n ( pl onuses)
'onus' also found in these entries (note: many are not synonyms or translations):