chicken out

US /ˈtʃɪk.ɪn aʊt/
UK /ˈtʃɪk.ɪn aʊt/
"chicken out" picture
1.

怖気づく, びびる, 尻込みする

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.
バンジージャンプを試すつもりだったが、土壇場で怖気づいた
He was going to ask her out, but he chickened out.
彼は彼女をデートに誘うつもりだったが、怖気づいた