'Great aunt' and 'Great uncle' are what your children properly call your own aunt and uncle. Your aunt and uncle are the brother and sister of your parent. Your parent is your children's grandparent.
They could just call her by her name, but in terms of relationships, your uncle's daughter is your first cousin and your children's first cousin, once removed.
You would be a great (or grand) aunt (or uncle) to your nephews (or nieces) children. However, they would normally just refer to you as aunt or uncle.
Fred, or if his name's not Fred, then whatever his name is.
If you're asking what relation he is to them, he's their first cousin.
Your uncle is your childrens' granduncle.
Uncle or Great Uncle.
Great Aunt.
If your a boy they would call you great uncle, if your a girl they would call you a great aunt.
The children of your husband's sister are your nieces or nephews, and you are their aunt, just as he is their uncle.
Your niece will call you her aunt or uncle.
Your brother's children call you their aunt if you are female, or their uncle if you are male. Their are your nieces and nephews.
You are a great great Aunt (or Uncle) to the grandson of your Nephew.
Great Aunt/Uncle
your uncle
Boys = "nephews", Girls = "nieces". If you are a man they will cal you "uncle" If you are a woman they will call you "aunt" or "auntie".
In most families they would call you aunt or uncle. It would technically be great aunt or great uncle.
Your uncle or aunt's children are called your cousins.
Just Aunty. That's it........ You can call your uncle's wife "Aunt" with her name afterwards. Example: Aunt Margaret
Great aunt.