expression, godan verb (-ku)
fail in one's social duties; neglect one's obligations
Used when someone does not fulfill a social or moral obligation, especially in the context of 義理 (duty, obligation, sense of honor). Often implies a breach of expected reciprocity or gratitude.
お世話になった人に挨拶もせずに帰るのは義理を欠く。
Leaving without greeting the person who helped you is failing in your social duties.
He always takes care not to neglect his obligations.