Aggression in a dream is often a sign that you are repressing feelings of anger in waking life.
Speaking or behaving aggressively in a dream is a way of releasing negative emotions without taking any risks.
Who is the person you are being aggressive toward in your dream?
If it is someone you know, think about whether there is something about their behavior that is troubling you, and whether it would be helpful to speak to them about it in a calm, polite, non-aggressive manner.
The person toward whom you display aggression in your dream can represent an abstract quality.
For example, a judge can represent rules and the law, so being aggressive toward a judge in a dream can mean that you are angry because you think you are the victim of unfair rules.
A dream that someone is aggressive toward you can mean that you feel that you are being bullied or victimized in waking life.
If you dream that you are aggressive toward a stranger or that a stringer displays aggression toward you, you may be having trouble accepting an aspect of your personality.