Barbican
bahr-bi-kuhn
Etymology: Middle English, from Anglo-French barbecane, from Medieval Latin barbacana
1) An outwork or forward extension of a castle gateway.
(Gies, Joseph and Francis. Life in a Medieval Castle, 225)
2) Outerwork of a castle, providing additional defence for the gatehouse.
(Prestwich, Michael. Armies and Warfare in the Middle Ages: The English Experience, 347)