English Reference
Noun

aggressor

n. countable
C1 Advanced US /əˈɡɹɛsɝ/ UK /ɐɡɹˈɛsɐ/ ag·gres·sor UK spelling aggressors

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.


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.

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

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

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

This entry
Origin Latin aggressor
Level C1 · Advanced
Frequency Occasional
Updated