Your grandfather's brother's grandson is your great uncle's grandson.
The grandchildren of great aunts and great uncles are your second cousins.
Two people whose grandfathers were brothers are second cousins to each other.
Your grandson.
what is my mater name
He is your grandson. If his father is your son, he is your grandson.
Second cousins.
할아버지 (Hara buhjee)
He would be your great-great uncle.
What is your great-great-great grand nephew?!
Your grandfather's brother is your great uncle.
Your father's grandfather is your great grandfather.
He would be your great great uncle, but you could call him whatever endearing name you both prefer. my great grandfathers brother or my great uncle
Grandson :)