短语 to chicken out 的意思是某人因为害怕而临阵退缩，退出了。

例句

Johnny says he is an action man but he chickened out of riding a horse.

Are you absolutely sure you want to go bungee jumping with me? I don't want you to chicken out at the last minute.

请注意

另一个短语 no spring chicken 则用来形容那些不再年轻的人，男女都包括在内。

I don't go partying every night any more. I'm no spring chicken and I need to have a good night's sleep.