shitbag
The word shitbag has very many meanings to it, however the most important will be listed

1. someone who is so worthless that they are about as useful as a bag full of shit 

2. an insult given to someone who is a collective piece of shit. term gathered from CKY videos

3. another term for a sewerage tank, as they hold an abundance of shit

4. a bowel, part of the human body
1. Roger: you know what dave?
Dave: what?
Roger: you are a worthless shitbag

2. Bill is a son of bitch shit bag that deserves a tyre iron upside the head

3. Robbo: did u see what happened to that minga bastard?
Jimbo: no, what?
Robbo: some cracker put him in the shit bag out the back

4. I think my shitbag is leaking