used in internet speak or car rego plates. the 4 is an A and the 3 represents an E. pretty simple really. for example, instead of John you're a wanker mate. It would be John you're a w4nk3r m8.
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".