The grandchild of your great grandmother's sister is your second cousin once removed.
Your grandfather's sister's grandchild is your second cousin.
Your great grandmother's sister's grandson is second cousin to one of your parents and is your second cousin, once removed.
Your grandmother's sister's children are your first cousins, once removed.
Second cousin
Your grandmother's sisters are your Great Aunts.
Great- grandmother.
great grandma
There is no word in the English language for a relationship between grandmothers of related grandchildren
There is no proper term for this particular familial place. I would suggest just his name or your step-father's grandson.
Gram? is that her grandmother if it is then it is your great grandmother
Your grandfather's brother's grandson is your great uncle's grandson. The grandchildren of great aunts and great uncles are your second cousins.
Your sister's son' son is her grandson. Your sister's grandson is your great nephew. You are his great uncle or great aunt.
You have no socially named relationship to your step-great-grandson-in-law's father. If you like, you might call him "son" or "Mr. ...." or simply call him by his first name.
The great grand father would be the great grand sire, I'm not sure what the grandson would be. I'm sorry.
Your brother's grandson is your great nephew.
Yes, your great grandmother's sister is your great-great aunt. Your great aunt is your grandmother's sister.