Adverse Definition

ăd-vûrs, ădvûrs

adjective

adverser, adversest

Acting or serving to oppose; antagonistic.

Adverse criticism.

American Heritage

Moving or working in an opposite or contrary direction; opposed.

Adverse river currents.

Webster's New World

Contrary to one's interests or welfare; harmful or unfavorable.

Adverse circumstances.

American Heritage

Unfavorable; harmful.

The adverse effects of a drought.

Webster's New World

Moving in an opposite or opposing direction.

Adverse currents.

American Heritage

Synonyms:

Antonyms:

Other Word Forms of Adverse

Base Form:

adverse

Comparative:

adverser

Superlative:

adversest

Middle English from Old French advers from Latin adversus past participle of advertere to turn toward ad- ad- vertere to turn wer-² in Indo-European roots

From American Heritage Dictionary of the English Language, 5th Edition
First attested around 1374, from Old French avers (French: adverse), from Latin adversus (“turned against”), past participle of advertere, from ad- (“to”) + vertere (“to turn”). See also versus.

From Wiktionary