Irish slang. Girl who is an absolute BOOT.neither attractive physically or with her personality.tends to scowl alot regardless of mood.along with absolute cunt probably the most offensive thing you can say to a girl.similar to geebag, but worse!
"That one i was with last night was an absolute gowlbag! i was the drunkest man in the world though"
"look at that fuckin gowlbag! you would think she'd sort herself out"