Source : Webster's Revised Unabridged Dictionary (1913)

Eskar \Es"kar\, or Esker \Es"ker\, n. (Geol.)
   See {Eschar}.

Source : WordNet®

esker
     n : (geology) a long winding ridge of post glacial gravel and
         other sediment; deposited by meltwater from glaciers or
         ice sheets