• synonyms


[on-er-uhs, oh-ner-]
  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.
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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


1. heavy, crushing, grievous; irksome, galling.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for onerosity

Historical Examples

  • Then the gratuitous and the common have gained all that onerosity and property have lost.

    Harmonies of Political Economy

    Frdric Bastiat

  • Property, Community, are two ideas correlative to the ideas of onerosity and gratuitousness, on which they are founded.

British Dictionary definitions for onerosity


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

Word Origin

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 onerosity



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

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Online Etymology Dictionary, © 2010 Douglas Harper