Fountain part?

Hello!

We have a garden fountain where this part has broken 🙁 it’s brass/copper and the pipe from the pump pushes onto it. This part then sits in the hole forming a seal so the water spills over the side of the fountain into the bowl below. There used to be a rubber grommet for a good seal below the flared top. It’s not threaded. Does anyone have an idea what this piece is called or where we might get a replacement? I’ve googled different terms and can’t find anything. Not knowing what it’s called doesn’t help lol.

Thanks in advance!