From King Dictionary of Contemporary English
Related topics: Family
grandmothergrand‧moth‧er /ˈɡrænˌmʌðə $ -ər/ ●●● S2 W2 noun [countable] SSFFAMILYthe mother of your mother or fatherRegisterPeople usually say gran (in British English) or grandma when talking to or about their own grandmother:My grandma used to make lovely cakes.
Examples from the Corpus
grandmotherThen she explained that she lived at the villa and that Leonie was her grandmother, and Lais and Leonore her half-sisters.His father died a few months after his birth and his grandmother then ruled as regent.I looked just like the young girl my grandmother had shown me in her photograph albums.If it turned out that my grandmother really was dying, I could fly back to be with her.The materials available to our grandmothers were either more toxic or less effective.Nevertheless the grandmother was a strong influence.Your grandmother believed we had indeed lost our souls.