whistle in the dark
US /ˈhwɪs.əl ɪn ðə dɑːrk/
UK /ˈhwɪs.əl ɪn ðə dɑːrk/

1.
虛張聲勢, 故作鎮靜
to try to make yourself feel more confident or less afraid by pretending to be brave or cheerful
:
•
He was just whistling in the dark, trying to convince himself that everything would be fine.
他只是在虛張聲勢,試圖說服自己一切都會好起來的。
•
Despite his brave words, I could tell he was just whistling in the dark about the company's future.
儘管他勇敢地說著,但我知道他只是在虛張聲勢,對公司的未來感到不安。