‘You see: Mr. Drogo, he married poor Miss Primula Brandybuck. She was our Mr. Bilbo’s first cousin on the mother’s side (her mother being the youngest of the Old Took’s daughters); and Mr. Drogo was his second cousin. So Mr. Frodo is his first and second cousin, once removed either way, as the saying is, if you follow me.’
I had a look at the family trees and I proudly managed to follow this complex reasoning except for the wording "once removed either way, as the saying is": no, I don't follow him there!
Does anyone with English as mother tongue know what that expression is supposed to mean?
In my own home country, removing healthy living cousins is a capital offense!