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outer fence; outer enclosure; outer block
outline; contour
城の外郭には堀が巡らされていた。
The castle's outer enclosure was surrounded by a moat.
外郭の石垣が地震で崩れた。
The outer wall's stone rampart collapsed in the earthquake.
遺跡の外郭を調査する計画が進む。
Plans to survey the outer enclosure of the ruins are progressing.