gran·dam \ˈgranˌdam, -_dəm\noun (-s) Etymology: Middle English graundam, from Old French grant dame, from grant grand + dame lady, mother 1.orgran·dame\-ˌdām, -_dəm\ a.: grandmother b.: old woman 2.alsogrand·dam\-nˌdamˌ -ndəm\: a dam's or sire's dam — used of an animal