A Glasgow Hug is specific to the city of Glasgow in Scotland, but instead of an actual Hug, it is a stabbing with a knife or a shiv.
This type of Hug has been very common to the city of Glasgow for many years.
Guy 1: You hear about Tony?
Guy 2: No, what happened?
Guy 1: Someone gave him a Glasgow Hug.
Guy 2: I'm sure he had it coming.