Definition of: gradation

(grā·dā′shən) noun
1. Orderly or continuous succession, progression, or arrangement, as according to size, quality, state, rank, or proficiency; regular advance upward or downward, as by steps or degrees.
2. A step, degree, rank, or relative position in an order or series; grade.
3. In art and architecture, a relative subordination or arrangement of parts so as to produce a desired effect; such a blending and variation of color and light as will produce effects of depth, relief, etc.
4. Ling. Ablaut. [<F <L gradatio, -onis a going by steps <gradus a step]
—gra·da′tion·al adjective
—gra·da′tion·al·ly adverb