Wedge (one up; Ger. Keil), in combat, the wedge-shaped formation of a unit or sub-unit, with one manoeuvre element in the lead and two in reserve behind; as opposed to the inverted wedge. When attacking in wedge formation, the element at the front automatically has the lead, the neighbouring elements maintain contact and guide their movement on it.
Source: Meyers Großes Konversations-Lexikon, 6. Auflage 1905–1909