A little pest who likes to burst into your room while your doing homework, or playing on your phone. They like to hit you, then like a little bitch, they tell your parents when you hit back. In other words...they are annoying. They are so annoying they make you feel likebanging your head against the wall so hard you lose all your brain cells.
You: *on your phone*
Younger sibling: *bursting into your room and runs up to you* Hey!
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.