P.I.A. 

A secret government organization known only as the P.I.A. Also known as the Poop Inspection Agency.

I was sitting on the porcelin throne when the P.I.A barged in, demanding to check out the Baby Ruths.

P.I.A. by Ampersand& June 2, 2003

P.I.A. 

Pain in the Ass.

That teacher is a major P.I.A.

I hate that dog/cat/goat/etc. I hope I can regift that P.I.A. to some other poor sod.

P.I.A. by Hbug13 Mariquita13 October 15, 2019

P.I.A. 

Pain in the Ass. Spelled out when used, like C.I.A.

“Don’t be such a P.I.A.”

P.I.A. by ElementaryMan February 5, 2020

P.I.A. 

Abbreviation for Pigeon Inspection Association. They Deploy Lots of agents worldwide and you’ll mainly see them in public places, such as school, the park, and roofs of buildings. They inspect your areas and surroundings, making sure that you guys can stay safe or that they can chill in your area. If you approach an agent, bring food or else they’ll fly away and inspect a different area.

Jack: Yo P.I.A. Is Deploying A Shit Ton Of Agents Here
Ron: They Inspecting This Place, That’s Why

P.I.A. by Hero Of The Soviet Union March 5, 2020

P.I.A 

agj- An acronym for “pain in my a**”
n- hemorrhoids

The man had a lot of P.I.A, and his friend was being a P.I.A about it.

P.I.A by Amazing Words September 12, 2019

P.I.A 

pain in ass

That person is such a P.I.A

P.I.A by yamomma101 February 8, 2023

P.I.A.O

Stands for 'Play in an oven', used to insult noobs on WoW.

Can be used like DIAF.

"All your base are belong to us!!!"
"Assholes, go P.I.A.O"

P.I.A.O by Holly. F May 24, 2008