後悔こうかい Common Noun Irregular Transitive Intransitive Noun English jmdict 1 noun (common) (futsuumeishi) noun or participle which takes the aux. verb suru transitive verb intransitive verbnouns which may take the genitive case particle 'no' regret;repentance;remorse 今更後悔しても無駄だ。 It's no use regretting it now.
Shirabe