You shoulden't do anything, your in trouble for a reason.
Your uncle or aunt's children are called your cousins.
Your great uncle's children are your parent's first cousins and your first cousins once removed.
Your child's children are your grandchildren. Your great uncle's children are your parent's first cousins and your first cousins, once removed. Your grandchildren and your great uncle's children are first cousins, three times removed.
Your uncle's first cousins are also your parent's first cousins and so are your first cousins once removed. Similarly his second cousins are your second cousins once removed.
You and your uncle's child are first cousins to each other. You and your uncle's grandchild are first cousins, once removed, to each other.
You don't, simple as that. You could say cousins if it's that important, or "my aunt's nieces and nephews on the other side," but there isn't an actual term for that except your "uncle's wife's siblings children."
You are first cousin, once removed to the children of your great uncle.
Your great uncle's kids are your parent's first cousins. His grandchildren are your second cousins.
They are your cousins.
The children of your grand uncle are First Cousins to one of your parents, so you and they are First cousins, Once Removed.
Your uncle's sons and daughters are your first cousins.
Phoebe and Hepzibah were cousins. Hepzibah was the daughter of Phoebe's uncle.