Extremely weak or worthy of ridicule. From the phrase, "Couldn't fight their way out of a wetpaper bag."
John is such a weakling, he couldn't fight his way out of a wet paper bag.
Yesterday's football match was rubbish, it was nothing but a wet paper bag fight.
By Carlynne
Wet Paper Bag
Another term for having the explosive shits really bad. Just imagine if your carrying a paper bag full of stuff and the bottom gets wet and tears open and everything falls out. Synonym for explosive diarrhea. Acronym: WPB
Oh man I have a wetpaper bag really bad, if you don't get me to the bathroom pronto, your car is going to get it.