noun
stronghold; fortified position
Refers to a heavily defended place, often used in military or strategic contexts. Can also be used figuratively for a firmly held position or bastion.
敵軍は山の上の堅塁に立てこもった。
The enemy forces holed up in a stronghold on the mountain.
その地域は保守派の堅塁として知られている。
The region is known as a stronghold of the conservatives.
Compound of 堅 (ken, 'firm, strong') and 塁 (rui, 'rampart, fort'). The exact historical derivation is uncertain, but the word is formed from kanji with meanings related to defense.