词根：-grad-, -gress-

【词根含义】：步,级

【词根来源】：来源于拉丁语名词gradus(步)和拉丁语动词gradior, gradi, gressus, sum(步行)。

【同源单词】：centigrade, degrade, downgrade, gradation, grade

前缀：retro-

【词根含义】：向后

【词根来源】：来源于拉丁语retro(re-回,再 + -tro方向)

【同源单词】：retrocede, retrograde, retrogress, retrospect, retrospective

词根词缀：grad-, -grade, -gred, -gree, -gress

【来源及含义】Latin: walk, step, take steps, move around; walking or stepping

【同源单词】ad eundem gradum, aggradation, aggression, aggressive, aggressively, aggressiveness

词根词缀：retro-, retr-

【来源及含义】Latin: back, backward, backwards; behind

【同源单词】arrear, regurgitant menstruation, retroact, retroaction, retroactive, retroactively