What does p and pd mean?

[Makdyn]

What does p and pd mean? I see that alot when something bad has happened. I think the p stands for prayer but the pd I can not get.

 

[Sparx]

prayers and pixy dust

 

[jen_uk]

Pixie dust

 

[Makdyn]

pixie dust .... now it finally clicks of course this is the dis