Source : Webster's Revised Unabridged Dictionary (1913)

Eschar \Es"char\, n. [L. eschara, Gr. ?: cf. F. eschare. See
   {Scar}.] (Med.)
   A dry slough, crust, or scab, which separates from the
   healthy part of the body, as that produced by a burn, or the
   application of caustics.

Eschar \Es"char\, n. [Ir.] (Geol.)
   In Ireland, one of the continuous mounds or ridges of
   gravelly and sandy drift which extend for many miles over the
   surface of the country. Similar ridges in Scotland are called
   kames or kams. [Written also {eskar} and {esker}.]

Source : WordNet®

eschar
     n : a dry scab formed on the skin following a burn or
         cauterization of the skin