Quick Question
 

Your grandfather's brother's son (or your father's cousin) is what relation to you? 2nd uncle? Nothing?

I'm gonna guess first cousins once removed.

2nd cousin?? I have no idea what that whole "once removed" crap means so it could very well mean 2nd cousin.

According to this page, it's second cousins. Very odd that someone who is your father's uncle is your cousin...

Wouldn't it be your father's cousin?

Paging Flere!!

I also don't know what "cousin once removed" means... but I'm assuming in your scenario GH they'd be some kind of cousin.

Woops, yeah sorry, that's what I meant.... odd that someone that is your father's cousin is also your cousin.

I've heard both second cousins and first cousins, once removed. Glad I could help.

From that posted chart (handy), I read it thusly:

My granfather and your father were brothers from the same parents. Thus, my great-grandparents were your grandparents. By the chart, that makes us first cousins. (First column, second box down on the chart) Since you are a step "older" than me on the family tree when we lay it out that way, we are said to be "once removed."

The removed portion refers to generational separation.

The cardinal number preceding cousins indicates how many genenrations are between the closest of the two and the pair's common ancestor. In this example, one of the two has only one generation between himself and the common ancestor. The common ancestor is your great-grandfather who is his grandfather. So his father is the only generation between him and your common ancestor. First cousins.

If he's your father's cousin, that's one generation above you on the tree, so he's once removed. First cousin, once removed.

Its definitely 1st cousins once removed.

1st Cousins share common grandparents.

2nd cousins share common great grandparents.

And so on as the common sire is more generations away.

The XXX removed designation is for those of different generations. Since your grandfather's brothers son is your father's first cousin, he would be your first cousin once removed. To your children he would be cousin twice removed. To your grandchildren, he'd be cousin thrice removed.

His children and you, on the other hand, would be second cousins.