English Reference

Word

aggressor

Phoneticsag·gres·sor, stress on the second syllable

US/əˈɡɹɛsɝ/

UK/ɐɡɹˈɛsɐ/

Countable noun

Definition

n. a person, group, or country that starts a fight or an attack without being provoked first.

n. a person or entity that initiates a hostile action or an unprovoked attack. Often used in legal or political contexts to distinguish the initiator from the party acting in self-defence.

Examples

“The international community identified the neighbouring country as the aggressor.”

“In many legal systems, the court must determine who was the initial aggressor before deciding if a claim of self-defence is valid.”

“Historians continue to debate whether the empire was a calculated aggressor seeking expansion or merely a reactive power responding to perceived threats on its borders.”

Examples

simple

“The international community identified the neighbouring country as the aggressor.”

contextual

“In many legal systems, the court must determine who was the initial aggressor before deciding if a claim of self-defence is valid.”

complex

“Historians continue to debate whether the empire was a calculated aggressor seeking expansion or merely a reactive power responding to perceived threats on its borders.”

Usage

Commonly used in the singular to identify a specific party in a conflict.

Real-World Examples

“They lie constantly, and you need to be really, really cautious while discussing with them,” ⁠he told the Reuters news agency, stressing that Russia was the aggressor in its conflict with Ukraine.”
Al Jazeera 1 Sept 2026
“The IRGC later said it had begun a “regretful response to the aggressors”, state broadcaster IRIB reported.”
The Guardian 2 Sept 2026

Etymology

From Latin aggressor (“attacker, assailant, aggressor”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.C1 AdvancedIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.7.0–8.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 5.0–5.595–113TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.945–990
Frequency
Occasional
Level
C1 · Advanced
Updated

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