资料来源 : pyDict

有等级的,渐次的,浓淡法上的

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Gradational \Gra*da"tion*al\, a.
   By regular steps or gradations; of or pertaining to
   gradation.

资料来源 : WordNet®

gradational
     adj : slowly and smoothly [syn: {gradatory}, {graduated}]