muster something up
phrasal verb with muster verb [ I or T ] uk/ˈmʌs.tər/ us/ˈmʌs.tɚ/
鼓起（勇气）;激起（力量）
If you muster up a feeling of courage or energy, you try hard to find that quality in yourself because you need it in order to do something.
[ + to infinitive ] She finally mustered up the courage to ask him for more money. 她最终鼓起勇气向他多要一些钱。