It's a insult used on a person who is a pain or useless. The insult reffers to when a male ejaculates on his pants and a stain is left where the semen (or in slang cum fell. Hence the use of "cum") . It's acronym form is CSOTPOS. Used by many teenagers and is not understood by most teaches so it is higly useful.
Jim: DAVE DAVE DAVE!
Dave: Shut up you cum stain on the pants of society
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".