adverse

[ ad-vurs, ad-vurs ]

adjective

1. unfavorable or antagonistic in purpose or effect:

   adverse criticism.

   Synonyms: unfriendly, inimical, hostile

   Antonyms: favorable

2. opposing one's interests or desire:

   adverse circumstances.

   Synonyms: catastrophic, calamitous, disastrous, unfortunate, unlucky, unfavorable

   Antonyms: favorable

3. being or acting in a contrary direction; opposed or opposing:

   adverse winds.

   Antonyms: favorable

4. opposite; confronting:

   the adverse page.

adverse

/ ˈædvɜːs; ædˈvɜːs /

adjective

1. antagonistic or inimical; hostile

   adverse criticism

2. unfavourable to one's interests

   adverse circumstances

3. contrary or opposite in direction or position

   adverse winds

4. (of leaves, flowers, etc) facing the main stem Compare averse

Confusables Note

The adjectives adverse and averse are related both etymologically and semantically, each having “opposition” as a central sense. Adverse is seldom used of people but rather of effects or events, and it usually conveys a sense of hostility or harmfulness: adverse reviews; adverse winds; adverse trends in the economy. Related nouns are adversity and adversary: Adversities breed bitterness. His adversaries countered his every move. Averse is used of persons and means “feeling opposed or disinclined”; it often occurs idiomatically with a preceding negative to convey the opposite meaning “willing or agreeable,” and is not interchangeable with adverse in these contexts: We are not averse to holding another meeting. The related noun is aversion: She has a strong aversion to violence. Averse is usually followed by to, in older use occasionally by from.

Derived Forms

• adˈversely, adverb
• adˈverseness, noun

Other Words From

• ad·verse·ly adverb
• ad·verse·ness noun
• un·ad·verse adjective
• un·ad·verse·ness noun

Word History and Origins

Origin of adverse¹

First recorded in 1350–1400; Middle English, from Anglo-French, Old French advers, from Latin adversus “hostile” (past participle of advertere ), equivalent to ad- ad- + vert- “turn” + -tus past participle suffix, with -tt- giving rise to -s-

Word History and Origins

Origin of adverse¹

C14: from Latin adversus opposed to, hostile, from advertere to turn towards, from ad- to, towards + vertere to turn

Synonym Study

See contrary.

Example Sentences

The study also found no adverse effects on lung tissue following immunization, highlighting the vaccine's safety.

From Science Daily

Dr Morris said this concerned him, as it meant the "industry in general" was not being warned of any "adverse" issues with these medicines.

From BBC

Participants experienced minor side effects from the treatment but none had serious adverse reactions.

From Science Daily

“My research indicates that significantly reducing Social Security benefits would likely have adverse effects on recipients' health, particularly for those with costly medical conditions,” McCauley said.

From Salon

On the contrary, they show adverse effects associated with coercion.

From Salon

Related Words

• conflicting
• detrimental
• disadvantageous
• inimical
• injurious
• negative
• unfortunate
• unfriendly

Adverse Vs. Averse

What's the difference between adverse and averse?

Adverse most commonly means unfavorable or hostile, as in adverse conditions, adverse weather, or adverse criticism. Averse means strongly opposed to or having a feeling of strong dislike toward something, as in I’m extremely averse to taking on debt.

Averse is often used in negative constructions, as in We are not averse to negotiations. It’s also used in the term risk-averse, meaning reluctant to take risks or tending to avoid risk.

Confusion can arise between the two terms because both are adjectives that involve unfavorableness or opposition. However, adverse typically describes circumstances, while averse typically describes the way someone feels toward something.

One way to remember which word is which is to remember that adverse, in a very general sense, means bad, which rhymes with the first part of the word. On the other hand, when you’re averse to something, you have a very strong opposition to it.

It may also be helpful to remember that the noun form of adverse is adversity, which means hostile or unfavorable conditions. The noun form of averse is aversion, meaning a strong feeling of dislike or opposition.

Here’s an example of adverse and averse used correctly in a sentence.

Example: I’m not averse to taking risks for the sake of adventure, but I just don’t think it’s safe to skydive in such adverse weather.

Want to learn more? Read the full breakdown of the difference between adverse and averse.

Quiz yourself on adverse vs. averse!

Should adverse or averse be used in the following sentence?

The medication had some _____ effects.