noun
vertical trench; ascending trench; slope trench
A trench or pathway cut into a natural slope, often used in fortifications or siege works. Contrasts with 横堀 (よこぼり), a horizontal trench.
See also: 横堀 (よこぼり)
城の防御のために、斜面に竪堀が掘られた。
A vertical trench was dug into the slope for the castle's defense.
竪堀は攻め手の移動を妨げる役割を果たした。
The ascending trench served to hinder the movement of attackers.
横堀 is a horizontal trench, typically running along the contour of a slope, while 竪堀 runs vertically up or down the slope.
Compound of 竪 (たて, 'vertical') and 堀 (ほり, 'ditch, trench'). The reading ほり becomes ぼり due to rendaku.