Note: in AM, use 'self-defense'
1.
Self-defence is the use of force to protect yourself against someone who is attacking you.
Richards claimed he acted in ~ after Pagett opened fire on him during a siege.
...courses in karate or some other means of ~.
N-UNCOUNT: usu with supp, oft in/of N
2.
Self-defence is the action of protecting yourself against something bad.
Jokes can be a form of ~.
N-UNCOUNT