If your great great uncle (the brother of your great grandparent) had a great great granddaughter, you would be third cousins, once removed.
Your uncle's great granddaughter is your first cousin, twice removed.
You and the granddaughter of your grandmother's brothers, and sisters, are first cousins.
If you are a woman, you are great great aunt to your niece's granddaughter. If you are a man, you are great great uncle to your niece's granddaughter. In either case, your niece's granddaughter is your great great niece.
You would be his Great Uncle or Great Aunt He in turn would be your Great Nephew.
The uncle's nephew would be first cousins with the uncle's children. So the nephew would be a first cousin twice removed with the great granddaughter.
Yes, she would be your great-aunt.
Your granddaughter's husband might be called your grandson-in-law, although the term is rarely used. Hissister is your granddaughter's sister-in-law, but is not related to you.
Your grandmother's nephew would be your parent's first cousin. They would be your first cousin once removed. Since the child of your cousin is a generation away from you they are the once removed.
The great great grand daughter would be my cousin sister.
Your grandson and your sister's grandson are second cousins to each other.
She would be your cousin.
Anyone's daughter's daughter is their grandchild, and your grandfather's brother is your great uncle. So this is a question about how you are related to your great uncle's granddaughter. The grandchildren of siblings are second cousins to each other, so your great uncle's granddaughter is your second cousin, once removed.