From Longman Dictionary of Contemporary Englishonuso‧nus /ˈəʊnəs $ ˈoʊ-/ noun [singular] formal RESPONSIBLEthe responsibility for somethingthe onus is on somebody to do something The onus is on the prosecution to provide proof of guilt.
Examples from the Corpus
onus• Whenever this happens, the onus is on you to control the call and steer the conversation to a successful conclusion.• Inevitably the onus rests on the buyers and users to specify the products needed.• It prefers to publish Charters laying the onus for provision of services on others.• By contrast the bottom up approach puts the onus on the employee to do a self appraisal and then discuss it.• Maybe this takes the onus off what goodness is.• The deputy judge concluded that the onus of establishing testamentary competence had not been discharged.• The onus is now on Untaet and the World Bank to prove their worth.• The onus will be on the accused to prove that they did not abuse or discriminate.the onus is on somebody to do something• As such foods become more widely available, the onus is on us to put our money where our mouths are.• Whenever this happens, the onus is on you to control the call and steer the conversation to a successful conclusion.• Therefore the onus is on Ireland to do the same to keep the dream alive.Origin onus (1600-1700) Latin “load” 