My brother's cousin's son, thrice removed.

So, a little debate of sorts broke out Christmas Eve while at my Grandma's house with the fam. If you want to call it a debate. It was really the room full of people questioning what it meant to be twice removed, relatively speaking. It began because my cousin asked if my son was his second cousin. And I said, yes, he would be his second cousin as we are first cousins, any offspring of either of us results in second cousins to each other. Then a few others piped in for whatever reason about the "removed" portion of when people say "my [insert relative here] twice removed" and when it was appropriate to say that & what exactly it meant. A few people had ideas or assumptions of what it means and so, the debate went from there and all they ended up doing was deciding what it didn't mean, and never figured out what it does mean. My step-sister-in-law was sure it was supposed to be used in reference to second cousins and my mom said, no, it's just plain second cousin, not second cousin twice removed. They argued about that for a good 5 min before my SIL finally gave up. Funny thing, I've also always wondered what it means to be "removed" from someone but never thought to ask & always just assumed everyone else knew & the occasion never came up to ask such a thing. So, what does it mean? Is it literal (as in divorced or deceaced) or generational (as in the second & third cousins) or something else completely? Can anyone explain? With references and bibliography, please.