Verb. To "jaff" or "jaff it about" would be to expose your gentalia and wave it or shake it about sillily, enthusiastically and proudly for
everyone to see. Perhaps
you would hold your trousers half down with one hand and raise the other
in the air while moving your hips around. This term originates from Oswestry, Shropshire and has soon spread across Mid-Wales and can even be heard in Brampton, near Carlisle in Cumbria...