To shout at someone so loudly in the recipents ear that their hair is blasted to one side, mimicking a side-parting hairstyle. This is often avoided by those in the military most likely to recieve such treatment, by sporting the 'crew cut' thusly
not giving the rapid exhalation of air any purchase upon which to lift said hair into this style. Originating in
South London (UK) this term is
spreading fast.