一蹶不振

yī jué bù zhèn

never to recover after a setback

Character by character

一yī
one

蹶jué
stumble

不bù
not

振zhèn
rise

失恋以后，他一蹶不振，整天待在家里。

After the break-up he fell apart and now stays home all day.

Tone: negative (criticism).

One fall and someone never gets back up.

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