self-sacrifice
noun /ˌself ˈsækrɪfaɪs/
  /ˌself ˈsækrɪfaɪs/
[uncountable] (approving)- the act of not allowing yourself to have or do something in order to help other people
- the courage and self-sacrifice of those who fought in the war
 - an act of heroic self-sacrifice