You and your great grandmother's nephew are first cousins twice removed.
Yes, you grandmother's great nephew is the grandchild of her sister or brother and thus your second cousin. The mother/father of the great nephew would be first cousin to one of your parents.
Your great great great great great great great grandmother's great great nephew is your third cousin, six times removed.
Your sister's son is her grandson and your great nephew. Some use the term "grand nephew."
If your great great grandmothers were sisters, your common ancestors are your great great great grandparents. That makes you 4th cousins.
Your sister's son is her grandson and your great nephew. Some use the term "grand nephew."
Your nephew's son isyour great nephew. You are his great aunt or great uncle.
You are your great nephew's great aunt if you are a woman, or his great uncle if you are a man.
Your nephew's daughter's son is your great grand nephew (or great great nephew). You are his great great aunt if you are a woman, or his great great uncle if you are a man.
A great uncle is the brother of the great nephew's grandfather or grandmother.
Your nephew's daughter is your great niece. Her son is your great great nephew. You are his great great aunt (if you are a woman) or his great great uncle (if you are a man).
not to be complicated , but if you have an uncle--> he has a nephew--> as you can see that's not complicated . And if you ask what is a uncles NEPHEW related to an uncles grandfather. in what way ....i would say the nephew is is the great gandfathers great grandson.
Your nephew's child is your great niece (if a girl) or your great nephew (if a boy).
The children of your grand nephew (or great nephew) are your great great nephews and great great nieces (depending on whether they are girls or boys).
The son of your great niece is your great great nephew.