Meaning of the word "lose one's nerve" in English

What does "lose one's nerve" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

lose one's nerve

US /luːz wʌnz nɜrv/
UK /luːz wʌnz nɜːv/

Idiom

to suddenly become afraid and unable to do something that you had planned to do

Example:
He was about to ask her out, but then he lost his nerve.
The climber lost his nerve halfway up the mountain and had to turn back.