Bailey/ˈbeɪli/ Definition 1 of 2Pro Tip 1/3Medieval Castles Understand 'bailey' as part of medieval castle architecture, often near a keep. The festival took place in the castle's bailey. Pro Tip 2/3Enclosed Space A bailey is a space surrounded by protective walls, not just any courtyard. They secured the castle's bailey against invaders. Pro Tip 3/3Historical Vocabulary 'Bailey' for castle courts is old-fashioned; use it for historical or fantasy settings. The blacksmith’s shop was in the lower bailey.