Soft and round like a pussy cat, a whole in the middle and split in two, that's what you call a ring-dang-doo

Ring-Dang-Doo is a nonsense slang word typically used to describe a women's genitals similar to "Pussy".

The word has no etymology and first appeared in a song by Sam the Sham and the Pharaohs but the word also made an appearance in the 2018 western action-adventure game Red Dead Redemption 2 in a campfire song.

The ring dang doo now what is that?
It's soft and round like a pussy cat
Got a hole in the middle and is split in two

Now that's what you call the ring dang doo!