How to say "cornerstone" in Japanese

• 礎いしずえCommon
  nounThe figurative cornerstone: the base on which a nation, institution, or belief is built and rests. It can also mean the literal foundation stone, and it is the usual choice for the metaphor.
• 礎石そせきCommon
  nounPrimarily the literal foundation stone laid at the base of a building. It can be used figuratively, but for the metaphorical 'cornerstone of the nation' sense, 礎 is the word you will usually want.
• かなめCommon
  nounThe keystone sense: the vital point that everything hinges on, the indispensable element of a team, plan, or system. It stresses being the crucial pivot rather than the base something is built on.

Use 礎 for the figurative cornerstone — the base a nation, institution, or belief rests on; 礎石 for the literal foundation stone in building; and 「かなめ」 for the keystone sense, the vital point everything hinges on.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 礎いしずえfoundation stone
• 礎石そせきfoundation stone
• 基石きせきcornerstone
• 土台石どだいいしcornerstone
• 柱石ちゅうせきpillar
• かなめvital point
• 積み石つみいしfoundation stone