Definitions

onerous

[on-er-uhs, oh-ner-] / ˈɒn ər əs, ˈoʊ nər- /

ADJECTIVE

difficult; requiring hard labor

Synonyms

STRONGEST

arduous backbreaking burdensome cumbersome demanding difficult distressing excessive exhausting grueling harsh intolerable laborious oppressive painful rigorous severe strenuous taxing troublesome weighty

WEAK

austere crushing embittering exacting exigent fatiguing formidable galling grave grinding hard headache heavy irksome merciless overpowering overtaxing plodding ponderous pressing responsible serious tiresome tiring toilsome vexatious

Antonyms

STRONGEST

calm easy effortless facile friendly gentle helpful mild nice simple trivial

WEAK

light

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In 1765, when Britain tried to enforce onerous fees on newspaper ads, “Sons of Liberty” groups rose up to oppose it.

From The Wall Street Journal • Apr. 15, 2026

Residents are criticizing a state law that requires permits and fees for building projects near Joshua trees, saying it’s opaque, confusing and onerous for those who want to improve or even maintain their properties.

From Los Angeles Times • Mar. 30, 2026

Recovering money after the fact is so much more onerous than intervening while it’s happening.

From MarketWatch • Mar. 30, 2026

Chemicals is one of the most important sectors in Europe's biggest economy but key industry players complain of high energy costs, onerous EU regulations and fierce foreign competition.

From Barron's • Mar. 26, 2026

The insubstantial frost feathers ensured that those last twenty feet remained hard, scary, onerous.

From "Into the Wild" by Jon Krakauer

Vocabulary lists containing onerous

300 Most Difficult "SAT" Words

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The Legend of Sleepy Hollow

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