uncasual
uncool, awkward and/or uncomfortable.
"That bitch came over to my mom's for Passover dinner and started dissing the whole Jewish race. It was SO uncasual!"
Uncasual Friday
When, on a Friday, one dresses up instead of dressing down
Guy 1: Hey kid, why are you wearing a suit to school?
Guy 2: What suit? These are my pajamas, it's Uncasual Friday
Guy 2: What suit? These are my pajamas, it's Uncasual Friday