Gradation

1. (n.) The act of progressing by regular steps or orderly arrangement; the state of being graded or arranged in ranks; as, the gradation of castes.
2. (n.) The act or process of bringing to a certain grade.
3. (n.) Any degree or relative position in an order or series.
4. (n.) A gradual passing from one tint to another or from a darker to a lighter shade, as in painting or drawing.
5. (n.) A diatonic ascending or descending succession of chords.
6. (v. t.) To form with gradations.