grandparent /ˈɡɹæn(d)pɛəɹənt/noun 1verb 1forms 3 noun1 •The parent of someone's parent.A 15-year-old orphan is being forced from the Arizona senior community where he lives with his grandparents after the homeowner’s association said it could face legal issues if he stayed. — 2020 verb1 •Synonym of grandfather. formsgrandparented · grandparenting · grandparents