adverse

adjective

ad·​verse ad-ˈvərs How to pronounce adverse (audio)
ˈad-ˌvərs
1
: acting against or in a contrary direction : hostile
hindered by adverse winds
2
a
: 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
adverseness noun

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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 Thyroid hormones are important for the normal development of the brain, which suggests developing fetuses and young children are especially vulnerable to the adverse effects of high fluoride exposure. Claire Bugos, Verywell Health, 16 Sep. 2024 Researchers are investigating ways to improve its efficacy and minimize adverse effects. William A. Haseltine, Forbes, 13 Sep. 2024 Valerian may have increased or adverse effects if taken with other medications with sedative properties. Melissa Nieves, Health, 13 Sep. 2024 Chronic lead exposure is associated with kidney issues, hypertension and adverse cognitive effects in adults, according to health officials. Kate Gibson, CBS News, 12 Sep. 2024 See all Example Sentences for adverse 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'adverse.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

14th century, in the meaning defined at sense 1

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

Dictionary Entries Near adverse

Cite this Entry

“Adverse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/adverse. Accessed 4 Oct. 2024.

Kids Definition

adverse

adjective
ad·​verse ad-ˈvərs How to pronounce adverse (audio)
ˈad-ˌvərs
1
: acting in an opposite direction
adverse winds
2
: opposed to one's interests
adverse testimony
especially : not friendly or favorable
adverse criticism
3
: causing harm
adverse effects of a drug
adversely adverb
adverseness noun

Legal Definition

adverse

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

More from Merriam-Webster on adverse

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