Medieval polearm (or, yet another big stick with sharp spiky bits). The voulge, like the bardiche, is a variation on the axe and the cleaver. The voulge is little more than a cleaver on the end of a long (7'-8') pole. It is also called the Lochaber Axe, a favorite amongst Scottish highlanders. There are several different styles of voulges, including military fork (similar to a two-pronged trident), bill hook (long, slender blade with a hook at the end), bill (long, straight, thin blade), guisarme (blade the shape of an elongated, hooked 'spade'), and glaive (various), depending on the exact style of the business end.
It should perhaps be noted that I have no real knowledge, experience, or particular expertise in these matters, whatsoever. Much like most of e2.