His selfless sacrifice inspired others to do the same.
courageous act
Frequency:
40
%
His courageous act saved the lives of many people.
noble deed
Frequency:
35
%
Her noble deed earned her the title of a hero.
brave heart
Frequency:
30
%
She showed her brave heart in the face of danger.
Idiomatic Expressions for hero
Phrase: be a hero in one's own eyes
Meaning: to see oneself as brave, noble, or admirable
Usage: Even though he failed to save the day, he was still a hero in his own eyes for trying his best.