后面 (hòu miàn) literally combines 后 (hòu, 'back' or 'after') and 面 (miàn, 'side' or 'surface'), together meaning 'the back side' or 'behind'. As a noun, it refers to the rear part of something — for example, the back of a building, a person, or an object. As a preposition, it indicates location behind something else, requiring a noun phrase after it (e.g., 桌子后面, 'behind the table'). It is neutral in register and widely used in both spoken and written Chinese.

Unlike the verb-based construction 在…后面 (zài… hòu miàn), 后面 alone cannot stand as a complete predicate without a locative particle or context; it usually appears with 在 or as part of a noun phrase. It contrasts with 前面 (qián miàn, 'front') and 上面/下面 (shàng miàn/xià miàn, 'above/below'), forming part of a core spatial vocabulary set learners encounter early.