It is a Scottish slang phrase used to signify general delight at something that has happened or as a greeting when meeting someone special. It is usually shouted at a loud volume. Some say its origins are from the Gaelic language meaning "Good fortune".
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".