堅けん

noun

strength; solidity; firmness

Rare literary or technical noun for hardness or unyielding quality; not used in everyday conversation.

• この材ざい質しつの堅けんは非ひ常じょうに高たかい。

  The firmness of this material is very high.

noun

armour; armor

Rare historical or classical term for armor; modern Japanese uses 鎧 (よろい) or 甲冑 (かっちゅう).

• 古こ文ぶん書しょに「堅けんをまとう」とある。

  In an old document, it says 'to don armor'.