大たい本ほん

noun

foundation; basic principles

Refers to the fundamental basis or underlying principles of something, often used in formal or abstract contexts.

• この理り論ろんの大たい本ほんは古こ代だいギリシャにある。

  The foundation of this theory lies in ancient Greece.

• 問もん題だいの大たい本ほんを理り解かいしないと解かい決けつできない。

  You can't solve the problem without understanding its basic principles.