ag·gres·sor | \ ə-ˈgre-sər \

Definition of aggressor 

: one that commits or practices aggression

Keep scrolling for more

Synonyms for aggressor


invader, raider

Visit the Thesaurus for More 

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

Police eventually determined Ragin was the primary aggressor. Campbell Lutz, ajc, "NFL veteran ‘Pacman’ Jones assaulted at Atlanta airport, police say," 12 July 2018 Police determined that the mother was the primary aggressor. Jeff Piorkowski/special To,, "Two mothers charged in domestic violence incidents involving their grown daughters: University Heights police blotter," 8 Mar. 2018 Police said Ragin was the aggressor and Jones defended himself., "Astros punish Ken Giles by sending him to Triple A," 12 July 2018 The sides first spoke through intelligence channels, with US analysts working to determine Kim's true willingness to abandon a nuclear program started by his grandfather and viewed by Pyongyang as a security blanket from outside aggressors. Kevin Liptak, CNN, "Trump, Kim set to meet for historic summit," 11 June 2018 His attorney, Joel Brodsky, has said his client was defending himself against drunken aggressors and did not steal the jacket. Dan Hinkel,, "Witness says officer punched 2, said he wouldn't get arrested because he was a cop," 17 May 2018 At the 2½-month initial trial in 2014, Iraqi witnesses spoke of the Blackwater convoy as the aggressor and said no cars or people in the area appeared to pose a threat. Alexa Corse, WSJ, "Witnesses Revisit 2007 Baghdad Shooting in New Blackwater Trial," 8 July 2018 So changing that mindset, getting that mindset back to being the aggressor, to being tough-minded, a team with grit and will, like all the great UConn teams have always had. Dan Greene,, "Dan Hurley on His Plan to Rebuild UConn, Learning From Auriemma and Calhoun and More," 20 June 2018 Babchenko called Russia an aggressor, and accused the country of killing children in its air support of Syrian President Bashar al-Assad's regime.. Angela Dewan, Antonia Mortensen And Denis Lapin, CNN, "Russia, Ukraine blame each other for journalist killing," 30 May 2018

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.

See More

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

Keep scrolling for more

Learn More about aggressor

Statistics for aggressor

Last Updated

20 Sep 2018

Look-up Popularity

Time Traveler for aggressor

The first known use of aggressor was in 1585

See more words from the same year

Keep scrolling for more

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 \

Kids Definition of aggressor

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


ag·gres·sor | \ ə-ˈgres-ər \

Medical Definition of aggressor 

: one who exhibits aggression

Keep scrolling for more

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).


the setting in which something occurs

Get Word of the Day daily email!

Test Your Vocabulary

Musical Words Quiz

  • gramophone
  • Which word describes a musical performance marked by the absence of instrumental accompaniment?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!