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

However, as Rothbard lays out, one of the most important concepts that often gets lost or forgotten in the fog of war is that violence may only be used to resist or punish the aggressor. —Connor Okeeffe, Oc Register, 29 Mar. 2026

With one quick push of a button, BLINGSTING Safety Alarms ear-piercing 125-decibel personal alarm sounds, intended to startle an aggressor and immediately alert bystanders that there’s a problem. —Tory Johnson, ABC News, 28 Mar. 2026

Two defense witnesses, including the doctor and a receptionist, supported her account, saying Ellis appeared to be the aggressor. —Nancy Dillon, Rolling Stone, 26 Mar. 2026

Congress, in contrast, has declared war in only five conflicts and only after an aggressor had already broken the peace, for example, Japan’s attack on Pearl Harbor. —Bruce Fein, Baltimore Sun, 23 Mar. 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