A chafe recieved between the upper thighs and asscrack brought about by sweaty activities such as walking back and forth or working out of doors. Produces a Baboon-likerash on the buttocks.
"Man, I got a serious case of monkeybutt bartending tonight!" or "Landscaping gave the rudest monkeybutt yesterday!"
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.