Slang term, commonly used in the North of England for plastic.
Particularly used in Teesside, Humberside and Yorkshire, as well as Merseyside
Across the UK, Manchester United fans are mainly said to live anywhere except Manchester. The common term for these fans in football circles are 'plastic mancs', or, as they are known in the North, Plaggy Mancs.
Plastic carrier bags are plaggy bags. Plastic macs become plaggy macs.