There has been much discussion over what a "gUncle" is. It is not a hip hop name I have coined for myself. I didn't even come up with it!
When my neice was small, she was told to call me "Uncle Mark" by her parents. For some reason, this came out of her mouth "guncle". This epithet was used for a few years before she was old enough to pronounce the two words individually.
Thank you Malia!