old grudge

• resentmentPersistent bitter displeasure
• bitternessSharp, unpleasant taste or feeling
• vendettaProlonged retaliatory conflict
• feudBitter ongoing rivalry
• revengePunishing a wrongdoer

spite · animosity · rancor · score · bad blood · wound · slight · betrayal · memory · festering · harbored · nursing · unforgiven · settling · payback · enemies · quarrel · insult

• resentmentresentful, grudge, bitterness, rancor, spite
• revengeretaliation, payback, vengeance, vendetta, blood feud