Adverse or Averse?

What Is the Difference between "Adverse" and "Averse"?

The Quick Answer


(adjective) "harmful" or "hostile"
  • I cannot work in such an adverse environment. correct tick


(adjective) "against" or "unwilling to."
  • John is averse to long meetings. correct tick
Top tip: "Averse" is always used with "to."
adverse averse
"Adverse" means "harmful" or "hostile" (e.g., "adverse effect from the medicine.") "Averse" applies to people and means "against" or "unwilling to." Of note, "averse" is used with "to" (e.g., "averse to hard work"). Even though their meanings are different, "adverse" and "averse" are easy to confuse because they sound so similar.

Quick Test on "Adverse" and "Averse"

It's your go. Select the correct one:

Using "Adverse"

"Adverse" is an adjective. It means "antagonistic," "opposing," "harmful," "hostile," or "unfavorable" small American flag (unfavourable small British flag).

Example sentences:
  • I cannot operate in such adverse conditions. correct tick
  • Adverse conditions including rain, snow, ice and fog affect your visibility. correct tick
  • He is not responsible for the adverse events in your life. correct tick

Using "Averse"

"Averse" is used with "to." It means "against," "strongly disinclined to," "unwilling to," or "loath to." (Most often, it refers to people.)

Example sentences:
  • Sarah has always been averse to smoking. correct tick
  • (Note that "averse" is used with "to.")
  • Are you averse to hunting? correct tick
  • The company staff are averse to change. correct tick

Top Tip

Note that averse is used with to, but adverse is not. So, if you've used the word to, you need averse not adverse.

Synonyms of "Adverse"

The most commonly used synonyms for "adverse" are "hostile," "unfavourable," and "harmful." Here are some examples of "adverse" aligned to those synonyms in sentences:
  • Hostile. They endured adverse weather conditions.
  • Unfavorable. Your decision will have an adverse impact.
  • Harmful. Strong coffee has an adverse effect on me.

Synonyms of "Averse"

Three common synonyms of "averse" are "disinclined," "unwilling," and "loath." These carry different strengths of negativity. Here are some examples in sentences:
  • Disinclined. I am averse to swimming in the bay.
  • (Averse is not always a strong idea. It can imply hesitancy due to uncertainty.)
  • Unwilling. She is averse to meeting you again.
  • (Averse can imply a reluctance.)
  • Loath. I am averse to working with that clown.
  • (Averse can imply repugnance.)

A Video Summary

Here is a 2-minute video summarizing the difference between "adverse" and "averse." video lesson

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This page was written by Craig Shrives.