means a mark left on the skin or other tissue after a wound has healed, or by extension any lasting trace of past damage.

from From Old French 'escare,' meaning a scab or eschar, which came from Late Latin 'eschara' and ultimately Greek 'eskhara' — a word that meant 'hearth' or 'fireplace' and then came to mean the scab formed by a burn. So the word still carries a faint smell of smoke: a scar was once, quite literally, the mark left where the fire had been.