what is a cousin once removed
It is a very common misconception that a first cousin once removed is the same as a second cousin, it is not. Your second cousin is the child of your parent's first cousin. Therefore, if you share grandparents with a first cousin, you share great-grandparents with a second cousin, great-great-grandparents with a third, and so on. The child of your first cousin is a first cousin once removed, your first cousin's grandchild is a first cousin twice removed, and also so on. It really is rather simple once you get the hang of it. Oh, and here's the really confusing bit: the system doesn't define directions up or down.