1. an expression of elation or agreement at something that causes excitement.

2. a term to be repeated when someone succeeds at a task or says something of wit; another way of "giving props" to someone.

3. a line that can be used to express interest in someone, similar to "How YOU doin?" or "Wassup giiiirl!"

4. what you ask someone when they really want Doritos.

Origin: The expression originated from instances in which someone at a party would make an alcohol run and would ask others what they wanted them to pick up. Literally, "What do you want from the store?"

In other words: "Whatever it is that you want from the store, I got it or will get it for you"

Examples:

When they played this dope ass jam at the club all my friends were like "OOOOH whatchuwantfromthesto"!!!!

(Fine ass girl walks into room)
"Ooh damn girl, whatCHUwantfromthesto?!"

Person 1: "Whatchuwantfromthes to?"
Person 2: "I want some Doritos!"
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