What does 後悔 mean?
後悔 is a Japanese noun meaning “regret, repentance” in English. It is written as 後悔 in kanji, こうかい in hiragana, and koukai in romaji. This word is part of JLPT N3 vocabulary.
Example sentence
今更後悔しても無駄だ。
It's no use regretting it now.