Vocabulary What does 悔いる (くいる, kuiru) mean? 悔いる (くいる, kuiru) means to regret. Quick factsReadingくいるRomajikuiruPart of speechichidan verb, transitive 悔いるくいるkuiruto regret1ichidan verb · transitive to regretKanji in this word悔regret, remorse