When a male finds a female that has a big chunky BOTTY.
Your mum shaked her gyatt last night
Gyatt is a term used to define that someone's butt is huge, typically another way to say, "God Damn!"
Sentences for this term are typically like "You've gyatt to be kidding me", or " I've gyatt something in my eye".
Gyatt, you have a big Booty!