1) A device that literally makes money, such as a coin press or a bill press.
2) A device or anatomical region that figuratively makes money, such as a "booty", "nice set of legs" or in rare cases a "brain." Body parts that come in pairs are generally referred to in the plural.
3) A device that indirectly makes money, such as a computer or guitar.
4) One who makes money, such as Bill Gates.
"Let's fire up the money maker. We have an order for $6 billion in 20s."
"Shake ya money maker baby!" (referring to the bottom)
"Shake ya money makers baby!" (referring to the breasts)
"Shake the money maker" (referring to the process by which a coin press is shaken to clear a jam)
"I wear a helmet to protect my money maker"
"I owe my success to my money maker... my PC!"
"I'm the money maker of the family"