后悔莫及

後悔莫及
hòuhuǐmòjí
too late for regrets (idiom); It is useless to repent after the event.

CEDICT

to be too late to regret

Wiktionary

事后懊悔，已来不及了。表示事情无法挽回。如：「少壮不努力，等到晚景凄凉，后悔莫及。」也作「后悔无及」。

重編國語辭典

Entry Composition

1 后悔 hòuhuǐ to regret; to feel remorse
2 莫 mò
  1. do not
  2. there is none who
3 及 jí
  1. and
  2. to reach
  3. up to
  4. in time for

Related entries

悔之无及 huǐzhīwújí too late for regrets (idiom); It is useless to repent after the event.
追悔莫及 zhuīhuǐmòjí too late for regrets (idiom); It is useless to repent after the event.