noun
Refers to the base stone of a building or, figuratively, the fundamental basis of something. Common in architectural, historical, and metaphorical contexts.
この寺院の礎石は千年以上前のものだ。
The foundation stones of this temple are over a thousand years old.
教育は国の発展の礎石である。
Education is the cornerstone of a nation's development.
Compound of 礎 (foundation, cornerstone) and 石 (stone). The word directly describes a stone used as a foundation, and its figurative use is a natural extension.