Mommy, what's a pimp?

So I posted in my other blog about pimp and hoe costumes for halloween.
Yesterday my almost 9 year old son was talking about pimping someones ride or something.
I asked him if he knew what a pimp was, naturally he thought it was something to make your car look cool.
How do you explain to an 8 year old what a pimp is in a way that will make him not want to use it?
On Halloween one of his classamtes was a pimp, he called himself a gangster which somehow seems better to me when I know it probably shouldn't.
Anyways, I explained that a pimp is someone who makes someone else do things to get money, and then the pimp takes that money away from the other person. He asked why they say you 'pimp' things like your car and I said that the pimp usually spends the money they get on flashy clothes and jewelry and stuff for their car, this was an acceptable explanation.
We talked for a bit and when I asked him what he learned today he said "A pimp is a guy, (or a girl), who makes a girl, (or a boy), do things that they don't want to do for money, then he takes the money away from them." I told him how proud I was of him and then he asked "Why do they say pimp in a kid's movie then?"
Doh! Huh? What kid's movie I say, figuring it would be Shrek or one of the 'kid's' movies that border on innapropriate.
Nope, it was Doogal.
We talked about it and my son figured the writers didn't want to get fired so that's why they left the word in the movie, the end decision was that it is up to us as consumers to support writers and movies that buck the trends and refuse to include innapropriate content.
It pretty much ended there but I feel like my son is an absolutely amazing little person. He is so insightful, intelligent and compassionate. When we were at the laundromat he helped a lady with the door then he put her buggy away for her, he always holds doors (sometimes to the point of annoyance because he will wait for someone who is 15 feet away to come through) and he's just an all around swell kid. He does tend to try to police others behaviour but it's almost always to keep others out of harm or trouble but we're working on it.
I am proud to say that I am responsible for raising him, he's a realy charm and I wish more kids were like him.