Иногда выводят из слова grade.
Но и у нас есть слово "Грядет" (гряСТи):

"grade (n.)
1510s, "degree of measurement," from French grade "grade, degree" (16c.), from Latin gradus "step, pace, gait, walk;" figuratively "a step, stage, degree," related to gradi "to walk, step, go," from PIE *ghredh- (cf. Lithuanian gridiju "to go, wander," Old Church Slavonic gredo "to come," Old Irish in-greinn "he pursues," and second element in congress, progress, etc.)."

Опять встает вопрос: кто первичнее - латины или мы.