When referring to uncles, aunts and cousins the term "removed" is used to designate a difference in generation. For example your cousins child would be your first cousin once removed. Your child and your cousin's child would be second cousins. Your first cousin once removed's (I refuse to cross threads at this point) child would be your child's second cousin, once removed. And so on.

I have never heard the term applied to 1st degree relatives, but I see no reason why it couldn't be. Hence your grandfather could be your father, once removed, and your great-great-great-great-great-grandfather would be your father, 6-times removed.

Aside: what comes after thrice?