A play on "LGBT" and means "Let's Go Brandon, Fuck Joe Biden." Originated in 2021, based on two phrases that have grown in popularity on the Internet and in the United States at large. Both phrases express displeasure with American President Joe Biden; LGBFJB is a means for them to encapsulate both in a convenient way.
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".