esker

from WordNet (r) 3.0 (2006)

esker
    n 1: (geology) a long winding ridge of post glacial gravel and
         other sediment; deposited by meltwater from glaciers or ice
         sheets

from The Collaborative International Dictionary of English v.0.48

Eschar \Es"char\ ([e^]s"k[~e]r or [e^]s"k[aum]r), 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, deposited by streams in meltwater
   channels under glaciers. Similar ridges in Scotland are
   called {kames} or {kams}. The spelling form {esker} is now
   the most commonly used, and the term is applied in geology to
   similar ridges created by glaciers anywhere in the world.
   Eskers vary in size and extent, but can be 100 feet high and
   up to 100 miles long. [Written also {eskar} and {esker}.]
   [1913 Webster +PJC]

from The Collaborative International Dictionary of English v.0.48

Eskar \Es"kar\, or Esker \Es"ker\ ([e^]s"k[~e]r), n. (Geol.)
   See {Eschar}.
   [1913 Webster]