Your grandfather's first cousin in your first cousin, twice removed.
Your grandfather's niece is a first cousin of one of your parents. Her son is your second cousin.
Your daughter's grandfather's brother's son is her mother's or father's first cousin and her first cousin, once removed.
Yes, you are related to your grnadfather's first cousin. Your grandpa's first cousin is your first cousin, twice removed.
cousin
Your grandmother is first cousins with cousin. Your parent would be the second cousin of the cousin's son. That would make you second cousins once removed.
Your grandfather's cousin is your cousin twice removed. Her husband has no direct relationship to you.
3rd cousin
Your first cousin is your son's first cousin, once removed.
The child of you father's first cousin is your second cousin.
The daughter of your first cousin is your first cousin, once removed.
Your first cousin's grandchild is your first cousin twice removed
The name given to the son of your aunt is first cousin or simply cousin.