aggressor

noun

ag·​gres·​sor ə-ˈgre-sər 

: one that commits or practices aggression

Synonyms of aggressor

• invader
• raider
• attacker

Examples of aggressor in a Sentence

Each country accused the other of being the aggressor.

a group of smaller states had formed an alliance to deter potential aggressors

Recent Examples on the Web

Major questions swirled in the immediate aftermath of the fatal encounter as witnesses from both sides of the protest gave conflicting statements about what led to Kessler’s fall and who the aggressor was. —Clara Harter, Los Angeles Times, 7 May 2026

My take is that the male aggressor probably isn’t the original mate, but was hoping to step into the role. —Joan Morris, Mercury News, 4 May 2026

Reséndiz was a -200 favorite, but Munguía — the former WBO junior middleweight champ — was the aggressor from the start and won by scores of 117-111, 119-109 and 120-108. —ABC News, 3 May 2026

Attorneys offer competing descriptions of fights Attorneys for Paul and Mortensen offered competing versions of fights between the pair, with each suggesting the other party was the aggressor. —Hannah Schoenbaum, Chicago Tribune, 1 May 2026

Word History

Etymology

borrowed from Latin, "attacker, assailant," from aggredī, adgredī "to approach, attack" + -tor, agent suffix — more at aggress

First Known Use

1585, in the meaning defined above

Rhymes for aggressor

• assessor
• compressor
• confessor
• depressor
• hairdresser
• necessar
• oppressor
• possessor
• processor
• professor
• repressor
• successor

Kids Definition

aggressor

noun

ag·​gres·​sor ə-ˈgres-ər 

: a person or country that attacks without reasonable cause

Medical Definition

aggressor

noun

ag·​gres·​sor ə-ˈgres-ər 

: one who exhibits aggression