A slaggy boat. Somebody considered untrustworthy, reguarly pulling snakey moves on friends and just generally being a c*nt. Hangs about with gangster crowd pretending to be a drug dealer type but never sold a penny's worth.
John, you cheeky fu*king slagboat wheres my puff?!?
A slang term used to identify your girlfriend.
Dave: "She is at home"
Andy: "Your slag boat is getting on my nerves"
Dave: "Sorry mate, i will have a chat with her"