What is a "double" Kohen? Does it just mean that your father and mother are both from Kohen families or is there more to it than that?

I've never heard of a "double" Kohen. Where did you read about it?

I didn't read about it. It was word of mouth. My exhusband used to always say he was a double Kohen, and his mother said so too.

Possibly it does mean, as you say, that the father was a Kohen and the mother's father was a Kohen. But there is no significance to it, as far as I am aware.

I have never heard of this one either, but I have to ask: Wouldn't a "double Cohen" pretty much be rote? I mean wouldn't that pretty much support the ideal od a pious family, by that I mean no intermingling of any other families, tribes, or nationalities?

I think that is somewhat what they meant. His mother spoke seven different languages, so perhaps there is a word or expression for "double Kohen" in another language, other than English.

But Walter, you forgot the obvious 4th:

On Purim or Simchas Torah when a Kohein carries around his son or a peer on his shoulders!

Quote "3. A cohen who has an identical twin. "

Actually, my 7 year old suggested maybe they're Siamese twins

A two-sided "cohen"?