On Guani is a phrase that is a way of saying that someone is telling the truth. Similar to other phrases such as "I swear to God." Other common uses are "On my mom," "On my grandma," "On my grandpa," "On gang," etc...
Person 1: I whipped out of that parking lot so fast, spinning the wheel, I 'bout flipped the damn car over. Then the police started following me, and I had to run away.
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.