The kanji 柱 primarily means "pillar," "post," or "support." It refers to a vertical structural element that provides support to a building or other structure. It represents the idea of something that stands upright and bears weight.

・On-yomi (音読み): チュウ (chuu) ・Kun-yomi (訓読み): はしら (hashira)

⚫︎ 電柱 (denchuu) Translation: Telephone pole or utility pole. ⚫︎ 大黒柱 (daikokubashira) Translation: The main pillar of a house (figuratively, the main supporter of a family). ⚫︎ 柱時計 (hashiratokei) Translation: A grandfather clock or a tall, freestanding clock.

The kanji 柱 is a phono-semantic compound (形声文字). The left side is 木 (ki), meaning "tree" or "wood," which provides the semantic component (meaning). The right side is 主 (shu), which provides the phonetic component (sound), indicating the pronunciation. Therefore, the character originally depicted a wooden pillar or post. The "wood" radical suggests the material, and the phonetic component helps with the pronunciation. Over time, it came to represent any kind of vertical support.