DictionaryaggressorInitiator of conflict
noun

aggressor

uh-GRES-er/əˈɡresər/

A person, group, or country that starts an attack or conflict.

The aggressor shoves the other man, who retreats defensively.

Man initiating a shove while the other retreats defensively.
Etymology

Stepping toward people could mean approaching them, but also attacking them. The agent ending makes an aggressor the one who takes that hostile initiative.

In context

Echoes of the British Crown15:25
look like the aggressor against people who refused to strike back.
Lord Irwin: Viceroy of India Navigating Reform, Empire, and Gandhi's Rise

More examples

  • Witnesses disagreed about who had been the aggressor.
  • The smaller country sought help against the invading aggressor.
  • The treaty promised a joint response to future aggressors.

Forms

aggressor · aggressors

aggression noun — Hostile action directed against another.

Similar words

attacker
Describes someone carrying out an attack, not necessarily initiating conflict.
instigator
Starts trouble but need not personally attack anyone.