adverse
Often confused with averse
- 1Unfavorable or harmful; actively opposing someone's interests or working against their welfare.
The medication carries a risk of adverse reactions in older patients.
Investors grew cautious amid increasingly adverse economic conditions.
Similarharmful, unfavorable, negative, detrimental, damaging
Oppositefavorable, beneficial, positive, advantageous
Note
Here the word does what its Latin parent adversus, "turned against," describes: ad- "to" plus vertere "to turn," the root also behind versus. English took it from Old French by around 1374. It pairs naturally with forces and conditions, from Robert Southey's "an adverse fortune" (1829) to R. C. Riley's "adverse grades" for uphill track (1960). It compares with more and most; adverser and adversest are rare and nonstandard.
- 2Opposed or contrary, standing against a person's interests or desires.
The witness gave testimony adverse to her own brother's interests.
The two companies hold adverse claims to the same patent, and neither will back down.
Similarcontrary, opposed, opposing, conflicting, hostile
Oppositefavorable, supportive
- 3Placed directly opposite something and facing toward it.
Note
This sense is about position rather than hostility. The adverse page is the one facing across the spread, and Byron's "Calpe's adverse height" (1809) is a height seen from the opposite side. Unlike the "unfavorable" meaning, it takes no more or most, because a thing either faces another or it does not. James Hogg's families "rather adverse to one another" (1835) sit on the line between facing and feuding.
Practice
Can you tell the meanings of adverse apart? Answer 2 quick questions from this page, or write your own sentence and AI will check it.
Origin
First attested around 1374, from Old French avers, from Latin adversus ("turned against"), the past participle of advertere, from ad- ("to") plus vertere ("to turn").