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

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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
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Recent Examples on the Web

The Obama-era rule — finalized in 2017 in the last days of the previous administration — requires mine operators to examine workplaces before miners begin their shifts and to make a record of adverse health and safety conditions. NBC News, "Trump administration cannot weaken Obama-era safety rule for miners, court says," 18 June 2019 Creating oppressively adverse conditions of detention, like those in Irwin County, Georgia, far away from family and legal counsel, causes despair and hopelessness, and forces these men and women to give up on their immigration claims. Rania Aniftos, Billboard, "21 Savage Donates $25,000 to Southern Poverty Law Center Following His ICE Detainment," 13 June 2019 Just before the 72nd minute, the referee halted play due to adverse weather conditions and there was a lengthy delay in proceedings, but the pattern of the match continued after the game resumed as Sweden continued to press for the opener., "Women's World Cup Recap: Netherlands Leave it Late Against New Zealand as Sweden Snatch Win," 11 June 2019 In his speech, Boutros said social factors and exposure to adverse childhood experiences have four times the impact on a patient’s health than his or her doctor, hospital, medications or surgeries. Leila Atassi,, "MetroHealth CEO Dr. Akram Boutros calls citizens to join Open Table, support programs to reverse effects of trauma and structural racism on public health," 7 June 2019 Many more suffered adverse health effects as a result of radiation poisoning. Josefin Dolsten,, "Former lawmaker hopes HBO’s ‘Chernobyl’ spurs change in Israel," 26 June 2019 She, along with eight of the other plaintiffs, described adverse health impacts from the wildfires that rage in and around their home towns practically every year. Carolyn Kormann, The New Yorker, "The Right to a Stable Climate Is the Constitutional Question of the Twenty-first Century," 15 June 2019 Not working often leads to loneliness and social isolation, which have a marked adverse impact on health; loneliness is as lethal as smoking 15 cigarettes a day, and social isolation increases risks of disease, hospitalization and death. Louise Aronson, Twin Cities, "Louise Aronson: I’m a geriatrician, and I’m fine with an 80-year-old running for president," 14 June 2019 Lab studies have shown adverse impacts of nanoplastics on aquatic organisms. Stephen Leahy, National Geographic, "Microplastics are raining down from the sky," 15 Apr. 2019

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.

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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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Statistics for adverse

Last Updated

17 Jul 2019

Look-up Popularity

Time Traveler for adverse

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

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More Definitions for adverse



English Language Learners Definition of adverse

: bad or unfavorable : not good


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

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More from Merriam-Webster on adverse

Rhyming Dictionary: Words that rhyme with adverse

Thesaurus: All synonyms and antonyms for adverse

Spanish Central: Translation of adverse

Nglish: Translation of adverse for Spanish Speakers

Britannica English: Translation of adverse for Arabic Speakers

Comments on adverse

What made you want to look up adverse? Please tell us where you read or heard it (including the quote, if possible).


appealing forcibly to the mind or reason

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