Define aggression: angry or violent behavior or feelings — aggression in a sentence. Aggression definition, the action of a state in violating by force the rights of another state, particularly its territorial rights; an unprovoked offensive, attack. Being aggressive often means being physical or showing force, but it is equally powerful as an adjective reflecting a forceful determination to get something. Home Sustainable Development Education Water Culture of Peace Human Rights Keywords Search. Seen fruitinator kostenlos online spielen Heard What made you want to look up aggression? Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 10,, visitors served. You Also Might Like Word of the Day chlorella. Aggression is hostile, purposely unfriendly behavior that can sometimes be violent. I kept you appraised at every stage I kept you apprised at every stage.