Is it farther or further?
late 14c., from Old French escare "scab" (Modern French escarre), from Late Latin eschara, from Greek eskhara "scab formed after a burn," literally "hearth, fireplace," of unknown origin. English sense probably influenced by Middle English skar (late 14c.) "crack, cut, incision," from Old Norse skarð, related to score (n.). Figurative sense attested from 1580s.
"bare and broken rocky face of a cliff or mountain," 1670s, earlier "rock, crag" (14c.), perhaps from Old Norse sker "isolated rock or low reef in the sea," from Proto-Germanic *sker- "to cut" (see shear (v.)).
The fibrous tissue that replaces normal tissue destroyed by injury or disease. v. scarred, scar·ring, scars
To mark with a scar or become marked with a scar.
To form scar.