up yer japsy Share definition Flag japsy being the skanger pronounciation of 'japseye', a part of the penis. this term is usually used as a slag or insult,to rub salt in the wounds. 'ha vinny i beat you in fifa forfit again, up yer japsy, your shite'. up yer japsy by strobalicious October 14, 2004 Get the up yer japsy mug.