The story
* co- + grandmother
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: the mother of one's son- or daughter-in-law, as common grandmother of their children; the relationship between women who have grandchildren in common; maternal grandmother vis-à-vis paternal grandmother. Full definition →
* co- + grandmother
Etymology from Wiktionary, CC BY-SA 4.0.