The granddaughter of your sister.
by Twight0931 July 30, 2017
Get the Grandsister mug.When your sister marries your grandfather.
by Big Man25 January 8, 2011
Get the grandsister mug.When your son/daughter has a baby with your mom/dad, said baby becomes the your grand-sister/grand-brother.
by Nullivoid December 21, 2020
Get the Grandsister/Grandbrother mug.by tjingtjong112 May 9, 2019
Get the grandsister mug.Your grandmothers sister.
by tjingtjong112 May 9, 2019
Get the grandsister mug.by I’m not Paul February 21, 2022
Get the Grandsister mug.