What does pishadoo mean?

"Pishadoo" is not a recognized word in any major dictionary or language. It's likely a made-up word, a nickname, or a misspelling of something else.

If you could provide more context, I might be able to figure out what it means. For example, where did you hear this word? What was the situation? Who said it?

Without more information, it's impossible to say what "pishadoo" means.