ad·​verse | \ ad-ˈvərs How to pronounce adverse (audio) , ˈad-ˌvərs \

Definition of adverse

1 : acting against or in a contrary direction : hostile hindered by adverse winds
2a : opposed to one's interests an adverse verdict heard testimony adverse to their position especially : unfavorable adverse criticism
b : causing harm : harmful adverse drug effects
3 archaic : opposite in position

Other Words from adverse

adverseness noun

Adverse vs. Averse

Many people find themselves confused when faced with the choice between adverse and averse. While these two adjectives have many similarities, they are not used interchangeably.

If you want to describe a negative reaction to something (such as a harmful side effect from medication) or dangerous meteorological conditions (such as a snowstorm), adverse is the correct choice; you would not say that you had an averse reaction to medication or that there was averse weather.

Averse is most commonly followed by the preposition to (as in "she is averse to shellfish"), but not in every case; you can, for example, describe someone as “risk averse." Normally, averse to signifies a degree of dislike and avoidance, but when preceded by the word not (as in “he was not averse to having another drink”), it may be used as a pointedly understated way to express an interest in something.

In short, adverse tends to be used to describe effects, conditions, and results; while averse refers to feelings and inclinations.

Examples of adverse in a Sentence

The Bankruptcy Code requires that debtor's counsel be disinterested and not have an interest adverse to the estate. Lawyers Weekly USA, 4 Oct. 1999 On more than one occasion his decrees provoked riots, and there were those who voiced adverse opinions on the Duke in public. — Alison Weir, The Princes in the Tower, 1992 The plant tolerates adverse conditions … — Dave Dunn, Fine Gardening, January/February 1991 all the adverse publicity really caused the movie star's popularity to suffer the adverse effects of the drug are too severe to allow it to be marketed
Recent Examples on the Web Furthermore, the governor said New Mexico and other border states would bear the brunt of adverse economic and social impacts likely to arise from the influx of migrants without additional planning by the federal government. Julia Musto, Fox News, 16 June 2022 All of which can have adverse impacts on the quality of patient care and the overall efficiency of healthcare organizations. Jacob Kupietzky, Forbes, 20 May 2022 The solutions will have to be sensitive to the communities most at risk to the adverse impacts of climate change and often with the fewest resources to comply with technological innovation. Stephanie Smith, Baltimore Sun, 18 May 2022 The Durham Town Board, however, completed a mandatory preliminary environmental study and, based on that, decided Bosque would not have significant adverse impacts on the area. New York Times, 12 May 2022 In all, the team found that rare specimen insects, rare pets, and service insects are readily available online, with almost no information on potential adverse ecological impacts. Doug Johnson, Ars Technica, 2 May 2022 There are enough exceptions in the act to deal with cases such as people having to move for employment reasons that adverse impacts will be ameliorated. Phillip Molnar, San Diego Union-Tribune, 25 Mar. 2022 In February, for instance, the European Union enacted a due diligence law that requires companies to identify adverse impacts that their activities have on human rights issues, such as child labor, and on the environment. Bruce Rule, Fortune, 7 Mar. 2022 The second installment of that report, released on February 28, makes the stark and game-changing revelation that these adverse impacts will only get worse and that there is an urgent need to adapt to those already underway. Saleemul Huq, Scientific American, 1 Mar. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'adverse.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of adverse

14th century, in the meaning defined at sense 1

History and Etymology for adverse

Middle English, borrowed from Anglo-French advers, borrowed from Latin adversus "turned toward, facing, opposed," from past participle of advertere "to turn toward, direct" — more at advert entry 1

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The first known use of adverse was in the 14th century

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Last Updated

12 Aug 2022

Cite this Entry

“Adverse.” Dictionary, Merriam-Webster, Accessed 18 Aug. 2022.

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More Definitions for adverse


ad·​verse | \ ad-ˈvərs How to pronounce adverse (audio) \

Kids Definition of adverse

1 : acting against or in an opposite direction adverse winds
2 : not helping or favoring adverse circumstances

Other Words from adverse

adversely adverb Bad weather adversely affected attendance at the fair.


ad·​verse | \ ad-ˈvərs, ˈad-ˌvərs How to pronounce adverse (audio) \

Legal Definition of adverse

: opposed to one's interests : operating to one's detriment an adverse verdict

More from Merriam-Webster on adverse

Nglish: Translation of adverse for Spanish Speakers

Britannica English: Translation of adverse for Arabic Speakers


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