noun
firm and solid; sturdy and indestructible; unshakable
Emphatic expression for something extremely solid, unbreakable, or unwavering. Often used figuratively for resolve, faith, or principles. The term carries a literary or formal tone and is not common in everyday conversation.
彼の決意は金剛堅固で、何があっても揺るがない。
His determination is unshakable; no matter what happens, it will not waver.
この城は金剛堅固な造りで、容易には落ちない。
This castle is built so solidly that it will not fall easily.
A four-character compound (四字熟語) combining 金剛 (diamond, adamantine) and 堅固 (firm, solid). The term originates from Buddhist texts, where it describes the indestructible nature of enlightenment or truth.