irregularly placed stakes (defensive obstacle)
Historical military term for stakes driven into the ground or underwater at irregular angles and intervals to impede enemy movement. Typically encountered in descriptions of fortifications or castle defenses.
Irregular stakes were set up around the castle.
They drove irregular stakes into the water to prevent enemy ships from entering.
Standard kanji spelling for this historical defensive structure.
Mixed kana-kanji spelling; used when the second kanji is considered difficult or uncommon.
Rare kanji form using 杙 instead of 杭; it is rarely used.
Compound of 乱 (ran, 'disorderly, irregular') and 杭 (kui, 'stake, post'), with rendaku voicing of the second element. The term directly describes the irregular placement of the stakes.