You are the nephew if you are male and a niece if you are female.
You are your grandniece's grandaunt or granduncle.
Well your son to your niece is cousin. so son to grandneice would be like a second cousin.
You would be the grand niece's great uncle.
Granduncle or aunt. "Greatuncle/aunt" is also correct and commonly used.
your second cousin
Great grand niece or nephew.
No, same thing to your grandparents.
Aunt's
Tom Sawyer's aunt was Aunt Polly.
Great aunt.
Your great aunt.
Aunt
Your aunt is your daughter's great aunt. Your daughter is your aunt's great niece.
If the dad's sister's aunt is also your dad's aunt, then your dad's aunt is your great aunt. However if she is not your dad's aunt, then she is your aunt's aunt and not necessarily related to you.
Your father's aunt is your great aunt.
Your father's aunt is your great aunt.
Your Aunt is your children's Great Aunt.
Your father's aunt is your great aunt.
aunt, ant