Butthole is teqnically the name for your anus. However butthole could also be used as an insulting name. For example "Taylah is a butthole".
An anus.
Hey does this thing on my butthole look infected to you?
Something that you can surprisingly fit a lot of stuff in
Bob- hey did you hear someone fit two raccoons in their Butthole?
Jimmy- really??? I can only fit three blue crayons!