Basically 'no lie' or 'for real'. You say it to show you're dead serious about what you just said. It comes from 'cap', which means a lie in Black and hip-hop slang.
Philly's all-purpose word that can mean basically anything: a thing, a place, a person, or an event. It works like 'thing' or 'thingy', and you figure out what it means from context.
Grab that jawn off the counter for me, and let's head to the jawn on South Street.
Gyatt is what people shout when they're hyped or impressed, usually after spotting someone with a big butt. It comes from an AAVE way of saying "God" or "Goddamn," and people also use it as a noun for the butt itself.
He saw her walk by in those jeans and just yelled "gyatt" across the whole parking lot.
If something's mid, it's just okay at best, nothing special and kind of disappointing. People use it to throw light shade at food, movies, music, or pretty much anything that got hyped up but didn't deliver.
Everyone said that burger place was amazing, but honestly it was mid.
In New England, especially around Boston, wicked just means "really" or "super." You put it in front of an adjective to crank it up, and it has nothing to do with being evil.
That lobster roll was wicked good, we have to come back here.
Yinz is how folks in Pittsburgh and Western Pennsylvania say "you all" when talking to more than one person. It works just like "y'all" does in the South.
Are yinz coming to the Steelers game on Sunday or what?
Rizz is your game with people you're into: the charm and smooth talk that makes someone want to date you or hook up with you. If you can flirt easily and get someone's number, you've got rizz. It probably comes from shortening "charisma."
He walked up to her at the party and got her number in two minutes, the guy has serious rizz.