A block of the Earth's crust, bounded by two normal faults, that has dropped downward in relation to adjacent portions.
Graben, from Ger. Graben "ditch, trench;" O.H.G. graban "ditch," grab "grave, tomb;" Goth. graban "ditch;" P.Gmc. *graban; cf. O.E. græf "grave, ditch;" E. a grave; PIE base *ghrebh-/*ghrobh- "to dig, to scratch, to scrape."
Foruzamin, from foru- + zamin. The first component foru- "down, downward; below; beneath;" Mid.Pers. frôt "down, downward;" O.Pers. fravata "forward, downward;" cf. Skt. pravát- "a sloping path, the slope of a mountain." The second component zamin, variant zami "earth, ground," from Mid.Pers. zamig "earth;" Av. zam- "the earth;" cf. Skt. ksam; Gk. khthôn, khamai "on the ground;" L. homo "earthly being" and humus "the earth" (as in homo sapiens or homicide, humble, humus, exhume); PIE root *dh(e)ghom "earth."