A extremestupid person. But you can't call them 'stupid', so you call them 'pid-stu'.
STUPID = STU-PID = PID-STU
1: You are so... pid-stu!
2: You are so mean! I am telling on you!
2: Teacher!
TEACHER: yes?
2: 1 called me a mean name!
TEACHER: What did they call you?
2: uhh... pid-stu?
TEACHER: What does that mean?
2: I dunno.
TEACHER: Tell me when 1 does something that is actually mean.
1: Hahaha! You are such a pid-stu 2!
The tentative, painful steps of a woman suffering from pelvic inflammatory disease. PID is caused by untreated VD or, less often, a botched abortion. A person doing the PID shuffle often leaves a foul, nauseating, greenish vapor trail and sometimes can be tracked home by following the droplets of cunt snot on the sidewalk.
Looka that ho doin' the PID shuffle over t' the ER. Bet she pulled a train last night! Choo-Choooooooo, ya nasty ol heifer!
ER nurse to resident: Here comes another blue waffle doing the PID shuffle. This one's yours, asshat, I've had enough cunt onion today...