adverse

adjective

ad·​verse ad-ˈvərs 

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

Did you know?

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.

Synonyms

• counter
• disadvantageous
• hostile
• inimical
• negative
• prejudicial
• unfavorable
• unfriendly
• unsympathetic
• untoward

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

The filing details the company's ongoing legal proceedings, including actions against former executives and other entities, with no material adverse effect expected on the company's financial condition. —Quartz Bot, Quartz, 14 Nov. 2024

While several free services to automatically delete all of an account’s posts exist, ones reviewed by NBC News either don’t guarantee against adverse effects like potentially suspending the account or require some technical work. —Kevin Collier, NBC News, 13 Nov. 2024

BFRs are linked to a host of adverse health effects including endocrine, liver and kidney toxicity, cancer, adverse effects of fetal and child development, and more, according to The National Institute of Health Sciences. —Kristin Hostetter, Outside Online, 13 Nov. 2024

The dose makes the poison Health groups have stated that adverse effects associated with fluoride occur when people are exposed to high doses, far higher than what is commonly set in community water systems. —Joseph Choi, The Hill, 5 Nov. 2024

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

Kids Definition

adverse

adjective

ad·​verse ad-ˈvərs 

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

ad·​verse ad-ˈvərs, ˈad-ˌvərs 

: opposed to one's interests : operating to one's detriment

an adverse verdict