[on-er-uhs, oh-ner-]
See more synonyms for onerous on
  1. burdensome, oppressive, or troublesome; causing hardship: onerous duties.
  2. having or involving obligations or responsibilities, especially legal ones, that outweigh the advantages: an onerous agreement.

Origin of onerous

1350–1400; Middle English < Latin onerōsus, equivalent to oner- (stem of onus) burden + -ōsus -ous
Related formson·er·ous·ly, adverbon·er·ous·ness, o·ne·ros·i·ty [oh-nuh-ros-i-tee] /ˌoʊ nəˈrɒs ɪ ti/, nounnon·on·er·ous, adjectivenon·on·er·ous·ly, adverbnon·on·er·ous·ness, nounun·on·er·ous, adjectiveun·on·er·ous·ly, adverbun·on·er·ous·ness, noun

Synonyms for onerous

See more synonyms for on
1. heavy, crushing, grievous; irksome, galling. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for onerous

Contemporary Examples of onerous

Historical Examples of onerous

British Dictionary definitions for onerous


  1. laborious or oppressive
  2. law (of a contract, lease, etc) having or involving burdens or obligations that counterbalance or outweigh the advantages
Derived Formsonerously, adverbonerousness, noun

Word Origin for onerous

C14: from Latin onerōsus burdensome, from onus load
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for onerous

late 14c., from Old French onereus, honereus (14c., Modern French onéreux) and directly from Latin onerosus, from onus (genitive oneris) "burden" (see onus).

Online Etymology Dictionary, © 2010 Douglas Harper