chicken out
US /ˈtʃɪk.ɪn aʊt/
UK /ˈtʃɪk.ɪn aʊt/

1.
desistir por medo, amarelar, dar para trás
to decide not to do something because you are too frightened
:
•
I was going to try bungee jumping, but I chickened out at the last minute.
Eu ia tentar bungee jumping, mas desisti no último minuto.
•
He was going to ask her out, but he chickened out.
Ele ia convidá-la para sair, mas desistiu.