Vulgar version of the word defecate, sometimes used interchangeably with the word poo, however most times you can find it being used to show that you are unpleasantly surprised by an event.
It also makes for a good summary of Candace Owens' personality
"Hold on I gotta take a shit real quick"
"Ah shit, I think mom found the cum sock"
"Man, the ending of GOT was kinda shit"