A Hitler, is a term used, in Britain to describe a style of pubic hair dressing, or topiary. Reffering almost exclusiveley to women. A variety of "Vag Tash". Think Brazzilian, but leaving a Hitler style moustache above the "vertical smile" or vulva.
The remaining pubic hair is trimmed to length. So as to give the appearnce resembling that of a Hitler style moustache.
Variations on the theme are commonplace. Alternatives to the Hitler moustache design include love hearts, angel wings, a teddy bear, even a football design, achieved by utilizing a mosiac effect of haired and shaved, or depilated areas.
"She has a nice clean waxed, beautiful vag, topped off with Hitler / a Hitler".