1. Acting or serving to oppose; antagonistic: adverse criticism.
2. Contrary to one's interests or welfare; harmful or unfavorable: adverse circumstances.
3. Moving in an opposite or opposing direction: adverse currents.
4. Archaic. Placed opposite.

[Middle English, from Old French advers, from Latin adversus, past participle of advertere, to turn toward : ad-, ad- + vertere, to turn.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.