aggression

American  

[uh-gresh-uhn] / əˈgrɛʃ ən /

noun

1. the action of a state in violating by force the rights of another state, particularly its territorial rights; an unprovoked offensive, attack, invasion, or the like.

   The army is prepared to stop any foreign aggression.

   Antonyms:

   peacefulness

2. any offensive action, attack, or procedure; an inroad or encroachment.

   an aggression upon one's rights.

3. the practice of making assaults or attacks; offensive action in general.

4. Psychiatry. overt or suppressed hostility, either innate or resulting from continued frustration and directed outward or against oneself.

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aggression British  

/ əˈɡrɛsə, əˈɡrɛʃən /

noun

1. an attack or harmful action, esp an unprovoked attack by one country against another

2. any offensive activity, practice, etc

   an aggression against personal liberty

3. psychol a hostile or destructive mental attitude or behaviour

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aggression Scientific  

/ ə-grĕsh′ən /

1. Behavior that is meant to intimidate or injure an animal of the same species or of a competing species but is not predatory. Aggression may be displayed during mating rituals or to defend territory, as by the erection of fins by fish and feathers by birds.

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Other Word Forms

• aggressor noun
• antiaggression adjective
• counteraggression noun
• preaggression noun

Etymology

Origin of aggression

1605–15; < Latin aggressiōn- (stem of aggressiō ), equivalent to aggress ( us ) ( aggress ) + -iōn- -ion

Explanation

Aggression is hostile, purposely unfriendly behavior that can sometimes be violent. A motorist who shows aggression for another may follow too closely, honk the horn, or otherwise try to intimidate. When someone deliberately tries to make another person feel intimidated or threatened, it's an act of aggression. Forceful, unfriendly behavior towards others is one example of aggression, and one country's hostile action toward another is also a kind of aggression. It's been used since the 1600s to mean "an unprovoked attack," from the Latin root word aggressionem, "attack," and in 1912 aggression was first used to mean generally "hostile behavior."

Example Sentences

"Given the usual tendencies of ants, I first assumed that I was observing aggression," Moffett said.

From Science Daily • Apr. 14, 2026

In contrast, McCullum believed England moved away from the aggression that had previously brought them success.

From BBC • Apr. 14, 2026

"Now it is our duty to act in response to this aggression," he said.

From Barron's • Apr. 9, 2026

As aggression escalated, the factions drifted into separate areas of the park.

From The Wall Street Journal • Apr. 9, 2026

There are creatures that interpret mere eye contact as aggression.

From "Catching Fire" by Suzanne Collins

Related Words

• assault
• encroachment
• invasion
• offensive
• onslaught
• raid