Adverse means unfavourable, harmful, or working against you, and it describes things or conditions (adverse weather, adverse effects, an adverse reaction). Averse means having a strong dislike of or opposition to something, and it describes people, almost always followed by to (averse to risk, not averse to a challenge). The most common error is writing adverse to change when you mean averse to change. Remember: aDverse describes Damaging conditions; avErse is a strong fEeling against.
Adverse and averse are near-homophones — they look almost identical and sound very similar, separated only by a single letter. Both come from the Latin root meaning “turned against,” which is exactly why they are so easy to muddle. Yet they behave very differently in a sentence. One describes harmful circumstances; the other describes a person’s reluctance. Once you know which word attaches to things and which attaches to people, the choice becomes straightforward.
At a Glance: Adverse vs Averse
| Word | Meaning | Part of Speech | Common Use |
|---|---|---|---|
| adverse | unfavourable, harmful, or working against you; describes things and conditions | Adjective | adverse weather, adverse effects, adverse reaction |
| averse | having a strong dislike of or opposition to something; describes people | Adjective (usually + to) | averse to risk, averse to change, not averse to |
Using “Adverse”
Adverse is an adjective that describes situations, conditions, or effects that are unfavourable, harmful, or likely to cause problems. It does not describe how a person feels; instead, it describes the external circumstances acting against someone. You will most often see it placed directly before a noun, as in adverse weather conditions.
Definition
Preventing success or development; harmful or unfavourable: The medicine can have adverse side effects. It frequently combines with words such as conditions, effects, reaction, impact, and publicity. In each case, the thing described is working against a positive outcome.
When to use it
- Describing harmful or unfavourable conditions: adverse weather, adverse conditions
- Describing negative results: adverse effects, an adverse impact
- In medicine: an adverse reaction to the drug
- Describing bad publicity or criticism: adverse publicity, an adverse report
- In formal or legal language: an adverse judgment, adverse findings
The flight was delayed because of adverse weather conditions.
Patients should report any adverse reactions to the new medication.
The scandal generated a great deal of adverse publicity for the company.
Rising costs had an adverse effect on the firm’s profits.
The committee reached an adverse decision and rejected the proposal.
adverse + noun (about things): adverse weather, adverse effects
adverse reaction / impact / publicity
Think: aDverse = Damaging, Disadvantageous conditions.
Using “Averse”
Averse is an adjective that describes a person’s feeling: a strong dislike of, or opposition to, something. It is almost always followed by the preposition to. Unlike adverse, it is rarely placed directly before a noun; it normally comes after a verb such as be or seem.
Definition
Having a strong dislike of or opposition to something; reluctant or unwilling: She is averse to taking risks. It is very common in the negative form not averse to, which is a polite, slightly understated way of saying that you quite like something: I’m not averse to the odd glass of wine.
When to use it
- Describing a person’s dislike or reluctance: he is averse to confrontation
- Always (almost) followed by to: averse to risk, averse to change
- In the common phrase risk-averse: a risk-averse investor
- In the understated not averse to (= rather likes): not averse to a challenge
- After verbs like be, seem, or remain: they remain averse to the idea
Many older investors are averse to taking financial risks.
He is deeply averse to any kind of confrontation.
The manager seemed averse to change of any sort.
I’m not averse to the occasional slice of cake.
A risk-averse company rarely invests in untested ideas.
averse + to (about people): averse to risk, averse to change
not averse to = quite likes: I’m not averse to a drink
risk-averse: a risk-averse investor.
The Key Difference: Conditions vs Feelings
The single most useful rule is this: adverse describes things and conditions, while averse describes people and their feelings. If something harmful is happening to you — bad weather, a side effect, negative publicity — that is adverse. If a person dislikes or is reluctant to do something, that person is averse to it. A reliable test is the word to: averse almost always takes to, whereas adverse sits straight in front of a noun.
Harmful conditions → adverse:
The drug may cause adverse effects. (= harmful results)
A person’s dislike → averse:
She is averse to taking the drug. (= she dislikes / is reluctant)
Notice how the same situation can use both words: a medicine might have adverse effects, and a patient might be averse to taking it. The conditions are adverse; the person is averse.
Common Mistakes
The new boss is adverse to taking any risks.
The new boss is averse to taking any risks. (a person’s dislike, with to)
Many employees are adverse to change.
Many employees are averse to change. (people’s reluctance, with to)
The medicine had several averse side effects.
The medicine had several adverse side effects. (harmful results, a thing)
We pressed on despite the averse weather.
We pressed on despite the adverse weather. (unfavourable conditions)
Special Expressions and Fixed Phrases
Several common expressions are fixed with adverse and describe harmful things:
- adverse weather conditions — bad or dangerous weather
- adverse effects / side effects — harmful results, especially of medicine
- adverse reaction — a harmful physical or public response
- adverse publicity — negative press or criticism
And several are fixed with averse and describe people:
- risk-averse — unwilling to take risks: a risk-averse investor
- averse to change — disliking or resisting change
- not averse to — a polite way of saying you quite like something
- averse to confrontation — preferring to avoid conflict
Link the spelling to the meaning. ADverse contains a D, so think of Damaging, Disadvantageous conditions — the harmful things that work against you. AvErse has an E where adverse has a d, so think of a strong fEeling against something — a person’s dislike. And if the word is followed by to, it is almost always averse (averse to risk), because feelings are aimed at something.
Frequently Asked Questions
Practice Adverse vs Averse
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Try Flash Cards →Related Confusing Words
- Affect vs Effect — another near-homophone pair that confuses many writers.
- Allude vs Elude — two similar-sounding verbs with very different meanings.
- Appraise vs Apprise — assess the value of something versus inform someone.
- Eminent vs Imminent — another easily muddled adjective pair.