An affectionate name for "grandmother," (esp. a somewhat
cold, possibly
drunk grandmother with aspirations of social standing.)
On the television
show Arrested Development, Maeby Fünke and George-Michael Bluth call their grandmother (Lucille Bluth) "Gangy" in many instances.
The etymology is unclear but it's frequent use in context makes the meaning clear. The spelling "Gangy" seems to be the generally-agreed upon spelling on Wikipedia, IMDB, and most
TV sites.
George Michael Bluth: "Was that Gangy who was just… " (slips on
Lucille's spilled
martini and falls)
Michael Bluth: "You all right? Sorry. Your grandmother had a little accident here."
George Michael Bluth: "Oh. Does that means she's gonna have to come live with
us?"