great grandmother
greatg·rand·mot·her
noun
1.
a mother of your grandparent
Origin
From great- + grandmother.
Related words
Broader terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.