Someone who is obscenely wealthy compared to the average working or middle class person and spends their money on likewise obscenely expensive products that have little to no real practicality but that are rather designed for the sole purpose of showing how much money the person has that they can afford such a thing.
Kevin: "Hey, check it out. I just bought the new Macbook Air. It'll make a sweet 2nd laptop. Oh, hold on, someone's calling me on my iphone."
Olivia: "Shut the eff up, rich bastard."