Aggressive

1. Tending or disposed to aggress; having or showing determination and energetic pursuit of one's own ends at the expense of others or mindless of others' needs or desires; characterized by aggression; making assaults; unjustly attacking; as, an aggressive policy, war, person, nation; an aggressive businessman; an aggressive basketball player; he was aggressive and imperious in his convictions; aggressive drivers. Opposite of unaggressive.
2. marked by self-confident ambition, competitiveness, energy and initiative; as, an aggressive young executive.
3. characteristic of an enemy or one eager to fight

Narrower related terms: bellicose, combative, pugnacious, scrappy, truculent ; hard-hitting, high-pressure ; hostile (used of attempts to buy or take control of a business: "hostile takeover"; "hostile tender offer"); predatory, rapacious, raptorial, ravening, vulturine, vulturous . See also: assertive, hostile, offensive.