Main Entry: oner·ous

Pronunciation: \ˈä-nə-rəs, ˈō-\

Function: adjective

Etymology: Middle English, from Middle French honereus, from Latin onerosus, from oner-, onus burden; akin to Sanskrit anas cart

Date: 14th century

1 : involving, imposing, or constituting a burden : troublesome <an onerous task>
2 : having legal obligations that outweigh the advantages <an onerous contract>

— oner·ous·ly adverb

— oner·ous·ness noun

synonyms onerous, burdensome, oppressive, exacting mean imposing hardship. onerous stresses being laborious and heavy especially because distasteful <the onerous task of cleaning up the mess>. burdensome suggests causing mental as well as physical strain <burdensome responsibilities>. oppressive implies extreme harshness or severity in what is imposed <the oppressive tyranny of a police state>. exacting implies rigor or sternness rather than tyranny or injustice in the demands made or in the one demanding <an exacting employer>.