棟

figuratively a central pillar or support

Phono-semantic compound:

木 (나무 목) — semantic, “wood, timber.”

東 (동녘 동) — phonetic, providing the sound.

Original sense: the main timber beam supporting the roof of a house. By extension, “pillar, backbone, central figure.”

동량(棟梁) — ridgepole and beam; figuratively, an essential person, a pillar of society

주동(主棟) — main beam of a house

국동(國棟) — figurative, the mainstay of a nation

Often paired with 梁 (beam, crossbeam), forming 棟梁, a classical idiom for “pillar of society.”