Irish slang from Limerick, Ireland. Can be used in a variety of ways. Can mean someone is not a nice person or can mean someone is a joker/messer.
For someone who isn't nice you might say "He/she is some Gowl!"
If someone is lying/joking with you, you might say "you're some gowl" or "go away You gowl"
Popular way of writing it is - "Gð¦"