Words related to *ghredh-
Latin, literally "A Step to Parnassus," the mountain sacred to Apollo and the Muses; from Latin gradus "a step; a step climbed; a step toward something" (from PIE root *ghredh- "to walk, go"). Also see Parnassus. It was the title of a dictionary of prosody used in English public schools for centuries as a guide to Roman poetry. The book dates from the 1680s. Also the name of a treatise on musical composition written in Latin by Johann Joseph Fux, published in Vienna in 1725, and of a much-used book of exercises for piano.
1550s, "to return to a former state or place, go back," from Latin regressus "a return, retreat, a going back," noun use of past participle of regredi "to go back," from re- "back" (see re-) + gradi "to step, walk" (from PIE root *ghredh- "to walk, go").
In astronomy, "appear to move in a backward direction," by 1823. The psychological sense of "to return to an earlier stage of life" is attested from 1926. Related: Regressed; regressing.