'渐变' (jiān biàn) literally combines 'gradual' (渐) and 'change' (变), describing a smooth, continuous transition — not sudden or abrupt. It's commonly used in both concrete and abstract contexts: in design for color gradients, in science for slow environmental shifts, and in language to describe subtle developments over time, such as behavioral changes in animals or ecological adaptations.

The term emphasizes process and continuity, often implying imperceptibility at any single moment but clear difference over time. While it functions grammatically as a noun (e.g., 'a gradual change'), it also appears adjectivally before nouns ('渐变过程', 'gradual-change process') or predicatively ('颜色渐变了', 'the color gradually changed'). It carries a neutral-to-formal register and is frequent in academic, technical, and descriptive writing — less common in casual speech.