‘台阶’ (tái jiē) literally combines ‘台’ (tái), meaning ‘platform’ or ‘stage’, and ‘阶’ (jiē), meaning ‘step’ or ‘grade’. Together, they refer to a single horizontal surface of a stair—what English calls a ‘step’ or ‘stair tread’. It is distinct from the entire staircase (楼梯, lóu tī), which includes both steps and risers. ‘台阶’ emphasizes the flat, walkable part you step on, whether outdoors (e.g., leading to a temple entrance) or indoors (e.g., in a modern building with raised flooring).

This word is commonly used in architectural, urban, and everyday descriptive contexts. It appears frequently in directions (e.g., ‘下三级台阶’ — ‘go down three steps’), safety warnings (‘小心台阶’ — ‘watch your step’), and literary descriptions of movement or setting. Unlike more technical terms like ‘踏面’ (tà miàn), ‘台阶’ is neutral, widely understood, and appropriate for both spoken and written Chinese.