pid-stu 

A extreme stupid 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!

pid-stu by Emma-NEM March 16, 2021

STU&PID 

Amber is Stu
&
Jessica is Pid

you would be called stu
&
your friend would be called pid

STU&PID by Jessica March 3, 2005

Pidstu 

A flipping of the syllables in stupid, invented by first-graders in that blissful year where the word stupid is a horrible swear.

Person 1: "That's so stupid!"
Person 2: "Oh my gosh, what did you just call it?"
Person 1: "Oh, sorry, it's so pidstu, then."

Pidstu by Borkborkbork August 14, 2010