A poop turd is merely a double noun... or adjective, depending on how you want to use the words. Regardless, a poop turd is someone who's a theif, pilferer, bugger, or shamus.
That filthy 'lil poop turd was stealin' my bagels!
by Gerald McBoingboing July 17, 2006
An extremely redundant word used by stupid people to describe poop. In fact, it isn't a real word
Wow, look at that big poopturd.
by Yellow corn man December 19, 2009