Dictionary.net

the act of defending yourself

the act of defending yourself

The act of defending one's own person, property, or reputation.

The act of defending one's own person, property, or reputation.

An affirmative defense to a crime. Self-defense is the use of reasonable force to protect oneself from an aggressor. Self-defense shields a person from criminal liability for the harm inflicted on the aggressor. For example, a robbery victim who takes the robber's weapon and uses it against the robber during a struggle won't be liable for assault and battery since he can show that his action was reasonably necessary to protect himself from imminent harm.