дедушка, pronounced "dye-doosh-kah"
Finns call santa Joulupukkijoulupukki :)
Your great great grandfather.
Your father's grandfather is your great grandfather.
Your great grandfather
Your great grandfather
Your great great grandfather.
Your grandfather's brother is your great uncle.
Your father's grandfather is your great grandfather.
He would be your great, great grandfather, but you could call him whatever endearing name you and he prefer -- Granddad, Papa, Grandpa, etc.
You call him grandfather.
Dyed Moroz - Grandfather Frost
Your grandfather's brother is your Great Uncle.