self–de·fense (US) or Brit self–de·fence 
/ˌsɛlfdɪˈfɛns/ noun
/ˌsɛlfdɪˈfɛns/ noun [noncount] 1 : the act of defending yourself, your property, etc.
▪ He argued that shooting the burglar was self-defense. ▪ She hit back in self-defense. 2 : skills that make you capable of protecting yourself during an attack
▪ Women are advised to take at least one class in self-defense. ▪ a self-defense instructor
▪ He argued that shooting the burglar was self-defense. ▪ She hit back in self-defense.
▪ Women are advised to take at least one class in self-defense. ▪ a self-defense instructor
