A nonsense substitute word used when you don't know the proper term for something or simply can't remember it. Derived from "Who'd have thunk it" and "what's this?".
My car broke down and Dad has to repair the whodathunkitwhatsis to get it running again.
Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".