Webster's Revised Unabridged Dictionary · 1913

Gradation

Gradation , noun

[Latin gradatio: compare French gradation. See Grade.]

1.
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.
The act or process of bringing to a certain grade.
3.
Any degree or relative position in an order or series.
The several gradations of the intelligent universe. — I. Taylor
4.
(Fine Arts) A gradual passing from one tint to another or from a darker to a lighter shade, as in painting or drawing.
6.
(Music) A diatonic ascending or descending succession of chords.

Gradation , transitive verb

To form with gradations. [Rare]