Can mean simply
1. Walking (as above tbh)
but also describes
2. An over-exaggerated style of walking characterized by a kind of swaying bouncing motion(ok that's not the best description just think almost comically exaggerated-walking) bearing a confident stance.
Most commonly employed by rude boys
(and I mean the chav
kind not the ska kind) seemingly to convey a "I'm the man!" persona but often overdone to the point of looking like an idiot.
All the same a slight bowl can help to make you appear confident (if only in the eyes of chav's) and can minorly improve your chances of getting started on by a gang of rude boys (as opposed to shuffling past nervously) I justify "the bowl" because being from essex(one of the lovely chav heartlands of england) I'm told by mates from nicer parts of the country that I sometimes have a slight bowl (albeit a subtle one)
My message bowling is ok, by all means cultivate an air of streetwise confidence but just try not to look silly.
ps I'm not anti-chav (some of my best mates fit well into that category) my comments simply reflect that I've never seen a skater/punk/greebo
with an excessive bowl or for that matter one that will try to start a fight with a complete stranger...
and your probably still thinking what is a bowl?
1. I'll bowl down there inna minute.
2. Look at the bowl on him! oh dear.
Should you spot a particularly bad perpetrator you could use the phrase "Do you want some fruit with that (bowl) mate!" should hopefully go right over anyones head who behaves in such a ludicrous manner, but you still have a fairly good chance of getting your head kicked in as even if they dont understand offence is easily taken.. oh but I digress.