Someone who attacks.

synoniemen: assailant, assaulter, attacker.

Roget 716: attack; assault, assault and battery; onset, onslaught, charge.    aggression, offense; incursion, inroad, invasion; irruption; outbreak; estrapade^†, ruade^†; coupe de main, sally, sortie, camisade^†, raid, foray; run at, run against; dead set at.    storm, storming; boarding, escalade^†; siege, investment, obsession^†, bombardment, cannonade.    fire, volley; platoon fire, file fire; fusillade; sharpshooting, broadside; raking fire, cross fire; volley of grapeshot, whiff of the grape, feu d'enfer [Fr.].    cut, thrust, lunge, pass, passado^†, carte and tierce [Fr.], home thrust; coupe de bec [Fr.]; kick, punch etc. (impulse) 276.    battue^†, razzia^†, Jacquerie, dragonnade^†; devastation etc. 162; eboulement [Fr.].    assailant, aggressor, invader.    base of operations, point of attack; echelon.    ... meer laten zien

Nederlands: aanrander, aanvaller, agressor, belager, zedendelinquent
Pools: agresor, napastnik

A confident assertive person who acts as instigator.

Nederlands: agressor
Pools: agresor