its a dance or motion in which you put each hand into a karate chop form and then hit your own chest - not too hard. this is known as josseling. origionated in liverpool england. it is also to have a wank, j.arthur rank, etc
' lets get in a mosh pit and jossel around all thesedirty emo's'
' i had a naughty jossel all over emma's face last night'