An act devoted to others' welfare or interests and not one's own. A self sacrificing act, that benefits others... performed by a truly selfless person. At a time when people need it most!
Person 1 - "My friends are living their lives too dangerously. Booze, drugs... Someone needs to show them it's not a sustainable lifestyle"
Person 2 - "What we need is a selfless act... They just need to see that you can die from living that lifestyle. Looks like it is up to me!"
(Person 2 has a near death experience after jumping off a balcony. person 2 survives with some lasting injuries. But due to that selfless act. His friends see the error in their ways, and change their lifestyles)