Characterized by or tending toward unprovoked offensives, attacks, or invasions. The aggressive behavior of the dog made the neighbors wary.
Vigorously energetic, especially in the use of initiative and forcefulness. The company adopted an aggressive marketing strategy to boost sales.
Assertive, bold, and enterprising. Her aggressive approach to problem-solving often led to quick results.
Intense or harsh in tone or manner. His aggressive tone during the meeting made everyone uncomfortable.
(Medicine) Progressing quickly and producing severe effects; difficult to treat. The patient was diagnosed with an aggressive form of melanoma.