To "turn up" is to get drunk and/or high, party, and forget about life for awhile. To "turn down" would be to get serious, go to work, and deal with reality.
Turn Down For What (the song) is a social commentary making the point that many people -- especially in "the hood" -- feel that even if they do "turn down" and do everything society expects of them, the deck is still so stacked against them that their lives still will not improve.
So why bother to turn down, if there's nothing to turn down for?
Complete a prostitution transaction from beginning to end. Starts with when a ho can catch a date, ends when she leaves the john, either to quit for a while or to go find another date. Also called to turn a trick.
A term used in an argument where the opposing side agrees to an insult or insults himself after a while in an effort to downplay the argument.
Person 1: Shut the fuck up loser. I bet you’re so fat you can’t see your feet while looking down.
Person 2: Yeah, that’s true lol
Person 1: Yeah turn the other cheek, pussy.