ag·​gres·​sor | \ ə-ˈgre-sər How to pronounce aggressor (audio) \

Definition of aggressor

: one that commits or practices aggression

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Synonyms for aggressor


invader, raider

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Examples of aggressor in a Sentence

Each country accused the other of being the aggressor. these pocket-size states had formed an alliance to deter potential aggressors

Recent Examples on the Web

Each party has a narrative around these events in which the other was the aggressor. Michael Brendan Dougherty, National Review, "Can Joe Biden Be America’s New Great Compromiser?," 21 June 2019 As early as September 1992, Biden publicly advocated for lifting the arms embargo that discriminated against the Bosnian Muslims, the principal victims of Serbian aggression, and for striking the aggressors with airpower. Marilynne Robinson, Harper's magazine, "Letters," 10 May 2019 An underdog in the primaries, Mr. Biden often displayed a sense of humor and comedic timing, playing the aggressor and pointing to his foreign-policy experience. Ken Thomas, WSJ, "Joe Biden May See Sharp Knives on Crowded Debate Stage," 24 June 2019 Iranian President Hassan Rouhani on Sunday repeated accusations that the United States is the aggressor in a series of tense incidents in and near the Gulf of Oman. Laura King,, "Trump says he’s open to Iran talks without preconditions," 23 June 2019 Officers determined that the primary aggressor was a woman, 48, who was arrested on a domestic violence charge., "Drunk driver with gun in car charged with nine offenses: University Heights police blotter," 4 June 2019 So, in the same way consuming antioxidant-rich foods aids your body in fighting off free radicals, topical antioxidants do the same for your skin, helping to offset daily aggressors like UV damage and exposure to air pollution. Rebecca Dancer, Allure, "Everything You Need to Know About Vitamin C, the Holy Grail of Skin-Care Ingredients," 23 May 2019 Over the eons, the long-term practice of killing unrepentant aggressors must have favored genes for more peaceful behavior. Richard Wrangham, WSJ, "Humans: The Domesticated Primates," 10 Jan. 2019 The service also wants to purchase 22 F-5 Tiger IIs, recently retired from the Swiss Air Force, to act as aggressor aircraft for the U.S. Navy and Marine Corps fighter pilots to train against. Kyle Mizokami, Popular Mechanics, "The Pentagon’s 2020 Budget Asks for Nearly 380 Aircraft, But One Buy Is Raising Eyebrows," 13 Mar. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'aggressor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of aggressor

1585, in the meaning defined above

History and Etymology for aggressor

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

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Statistics for aggressor

Last Updated

12 Jul 2019

Look-up Popularity

Time Traveler for aggressor

The first known use of aggressor was in 1585

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More Definitions for aggressor



English Language Learners Definition of aggressor

: a person or country that attacks another : a person or country that starts a fight or war


ag·​gres·​sor | \ ə-ˈgre-sər How to pronounce aggressor (audio) \

Kids Definition of aggressor

: a person or a country that engages in hostile action without reasonable cause


ag·​gres·​sor | \ ə-ˈgres-ər How to pronounce aggressor (audio) \

Medical Definition of aggressor

: one who exhibits aggression

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Comments on aggressor

What made you want to look up aggressor? Please tell us where you read or heard it (including the quote, if possible).


to form ideas or theories about something

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