‘居中’ literally combines ‘居’ (to reside, to be situated) and ‘中’ (center, middle), meaning ‘to be positioned in the center’ or ‘centrally located’. It functions primarily as an adverb describing placement—e.g., a button placed at the center of a screen—or as an adjective describing something’s central position—e.g., a building situated at the heart of a city. Unlike standalone nouns like ‘center’ (中心), 居中 emphasizes location *relative to surrounding elements* and is commonly used in spatial, visual, or organizational contexts.

The term appears frequently in design, architecture, cartography, and interface descriptions, where precise spatial relationships matter. It carries a neutral, formal tone and is rarely used in casual speech about people or emotions. While it may appear in written instructions or technical documents, it is not typically used for abstract centrality (e.g., ‘central idea’) — for that, 中心 or 核心 is preferred.