Scummer - An individual who supports Manchester United. Usually without actually having been born or even visited Manchester. This term is especially used by Leeds United fans!!!
You dirty scummer!! = Oi you horrible dirty man utd fan
A term of abuse used by football fans for supporters of a rival team. It originates from the word scum, which was first used by fans of London teams, such as Millwall, in the late 1960s. Nowadays, fans of many teams use it. For example, Lincoln fans call Scunthorpe fans the Scummers and it is also the name Leeds fans give to Manchester United fans.
The first recorded use of the word scummer dates back to 1585. It referred to one who scours the sea, a rover or a pirate. For many years it was a nickname for pirates or buccaneers. Then in the twentieth century football fans, especially fans of small clubs, began to use it for their rivals. Nowadays, Luton fans use it as a nickname for Watford, as do Grimsby fans for Hull.
Spanish treasure ships were attacked by English scummers off the coast of Hispaniola.