The Chinese word **脊柱 (jǐzhù)**, meaning "spine" or "vertebral column," is a compound noun formed through semantic combination. It combines the character **脊 (jǐ)**, which means "back" or "ridge" and specifically refers to the spinal area, with **柱 (zhù)**, which means "pillar" or "column." Together, they create the vivid metaphorical image of the **"back pillar,"** perfectly describing the spine's central, supportive role in the skeletal structure, much like a pillar supports a building. This formation is typical of Chinese, where two meaningful characters are joined to create a new, conceptually clear term.