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adj B2 Upper-Intermediate Common

adverse

AD-vuhs

Adverse (adj) means unfavorable or harmful; working against someone's interests. Example: “The medication can cause adverse side effects in some patients.”

adj
1
Unfavorable or harmful; working against someone's interests.
"The medication can cause adverse side effects in some patients."
"Adverse weather conditions delayed the flight for hours."

How to Use Adverse

Learner’s notes

In plain EnglishBad, harmful, or working against you.

Common mistake

Adverse describes conditions or effects ("adverse reaction"); averse describes a person's feelings ("averse to risk"). They're easy to swap by mistake.

Easily confused with
Common pairings
adverse effects adverse conditions adverse reaction

Word Forms

more adverse comparative, adverser comparative, most adverse superlative, adversest superlative

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Test yourself on “adverse” A quick quiz — meaning, synonyms & usage

Fill the Gap

Can you complete this real example?

The medication can cause _____ side effects in some patients.

Etymology

From Old French avers, from Latin adversus, "turned against" — from ad- ("to") plus vertere ("to turn").

Origin: Latin

Antonyms

Rhymes for adverse

See all rhymes for adverse →

Frequently Asked Questions

What does “adverse” mean?

The word “adverse” means unfavorable or harmful; working against someone's interests. In plain terms, bad, harmful, or working against you.

How do you pronounce “adverse”?

“Adverse” is pronounced AD-vuhs (/ˈæd.və(ɹ)s/ in IPA).

How do you use “adverse” in a sentence?

Here is “adverse” used in a sentence: “The medication can cause adverse side effects in some patients.”

What is the opposite of “adverse”?

The opposite of “adverse” — its antonyms — is proverse.

What part of speech is “adverse”?

“Adverse” is an adjective.

Where does the word “adverse” come from?

The word “adverse” comes from Latin. From Old French avers, from Latin adversus, "turned against" — from ad- ("to") plus vertere ("to turn").

Is “adverse” a common word?

“Adverse” is a fairly common word in modern English, usually learned at around the B2 level.

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