your courage/will/nerve fails (you)NOT HAVEif your courage etc fails, or if it fails you, you suddenly do not have it when you need it 你的勇气/意志/胆量消失 She had to leave immediately, before her courage failed her. 她必须趁自己还有勇气马上离开。
→ your courage/will/nerve fails (you) at fail1(3)