[Jenk]

> wth does "first cousin once removed" even mean?

It is using a very well established (i.e., has been used for a long time) terminology to describe familial relationships.

The "first" refers to how many horizontal genealogy lines are crossed (self -> sibling -> first cousin -> second cousin -> etc.) the "once" refers to the vertical, so the "first cousin once removed" refers to either your cousin's parent or child, and as we refer to our cousin's parents as aunt or uncle, we usually conclude that your "first cousin once remove" is your aunt/uncle's grandchild, ergo your [first] cousin's child.

[riffic]

I was going to reply with a similar explanation but then upon a reread it seemed like a flippant remark that didn't seem like an earnest inquiry.

do people just not know how to Google things these days?