2 - Used to describe a drink that causes such a night.
The phrase Luke Gaffney derives from an actual person, one Mr Luke Gaffney, a rugby player from the North of England. When questioned about his drunken actions, Mr Gaffney frequently replied "I can't remember" in a thinly veiled attempt to preserve his dignity.
B) I don't know, it was a bit of a Luke Gaffney.
2. A) I'll have a Luke Gaffney please.