Flag

A larger/chubby/obese/ fat person that acts or dresses like a slag. A mash up of fat and slag.

Girl 1: "Omg! Have you seen Katie today?"
Girl 2: "Why is she such a flag?!"

Guy 1: "Don't know what you saw in Becka mate she is such a flag!"
Guy 2: "I know, her legs were like tree trunks."

2👍 7👎