Billiam
When you're full name is Bill, and people ask what your "full" name is and you say Billiam (cause William's kinda weird if your full name is Bill).
Example:
Guy 1: I have a question Bill?
Bill: yeah?
Guy 1: Is your full name William?
Bill: Uh no it's uh... Billiam, yeah.
Guy: ah nice to know :D
Guy 1: I have a question Bill?
Bill: yeah?
Guy 1: Is your full name William?
Bill: Uh no it's uh... Billiam, yeah.
Guy: ah nice to know :D