aggressor

noun

ag·​gres·​sor ə-ˈgre-sər 

: one that commits or practices aggression

Synonyms

• invader
• raider

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

The pair have taken shots at each other over the years, with Shaq being the primary aggressor, sporadically insulting his predecessor with unflattering jokes and blatant slights. —Preezy Brown, VIBE.com, 7 Jan. 2025

Finally, the Moisture Shield seals in the deep hydration and protects against environmental aggressors. —Angelina Villa-Clarke, Forbes, 11 Dec. 2024

On the campaign trail, Trump promised to move quickly toward cease-fire talks in Ukraine and to negotiate a peace deal with Russia, the aggressor in the conflict. —Elie Tenenbaum, Foreign Affairs, 3 Dec. 2024

That changed Sunday, when the primary objective was to be the aggressor. —Jared Weiss, The Athletic, 29 Dec. 2024

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

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