1. The grandmother of one's stepmother or stepfather.
2.The stepmother of one's grandmother or grandfather.
3.The mother of one's grandmother's husband or grandfather's wife; but not their biological great-grandmother.
2.The stepmother of one's grandmother or grandfather.
3.The mother of one's grandmother's husband or grandfather's wife; but not their biological great-grandmother.
by Stepman December 11, 2017
Get the Step Great-Grandmothermug. The great-great-grandmother of one's spouse.
My great-great-grandmother-in-law is a good person.
by Rwopazaq November 24, 2019
Get the great-great-grandmother-in-lawmug. 
Get the 5X-grandmothermug. Great-great-great-great-great-grandmother.
My 6X-grandmother is a good person.
by N8953SW June 26, 2021
Get the 6X-grandmothermug. James: bro i love your gran
me: ikr its wierd to think she has had sex before
james: wtf *leaves and never talks to me again*
me: *cries knowing i lost my best friend and my gran has had sex before*
My grandmother is the mother of my mother.
me: ikr its wierd to think she has had sex before
james: wtf *leaves and never talks to me again*
me: *cries knowing i lost my best friend and my gran has had sex before*
My grandmother is the mother of my mother.
by sexymustardman December 30, 2021
Get the Grandmothermug. 
Get the great-great-great-grandmothermug.