The Collaborative International Dictionary of English v.0.48:

Glacier \Gla"cier\, n. [F. glacier, fr. glace ice, L. glacies.]
   An immense field or stream of ice, formed in the region of
   perpetual snow, and moving slowly down a mountain slope or
   valley, as in the Alps, or over an extended area, as in
   Greenland.
   [1913 Webster]

   Note: The mass of compacted snow forming the upper part of a
         glacier is called the firn, or n['e]v['e]; the glacier
         proper consist of solid ice, deeply crevassed where
         broken up by irregularities in the slope or direction
         of its path. A glacier usually carries with it
         accumulations of stones and dirt called moraines, which
         are designated, according to their position, as
         lateral, medial, or terminal (see Moraine). The
         common rate of flow of the Alpine glaciers is from ten
         to twenty inches per day in summer, and about half that
         in winter.
         [1913 Webster]

   Glacier theory (Geol.), the theory that large parts of the
      frigid and temperate zones were covered with ice during
      the glacial, or ice, period, and that, by the agency of
      this ice, the loose materials on the earth's surface,
      called drift or diluvium, were transported and
      accumulated.
      [1913 Webster]

WordNet (r) 3.0 (2006):

glacier
    n 1: a slowly moving mass of ice

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "glacier":
   Dry Ice, berg, calf, cryosphere, firn, floe, frazil, frozen water,
   glaciation, glacieret, glaze, glazed frost, granular snow,
   ground ice, growler, ice, ice banner, ice barrier, ice belt,
   ice cave, ice cubes, ice dike, ice field, ice floe, ice foot,
   ice front, ice island, ice needle, ice pack, ice pinnacle,
   ice raft, ice sheet, iceberg, icefall, icequake, icicle, jokul,
   lolly, neve, nieve penitente, pack ice, serac, shelf ice, sleet,
   slob, sludge, snow ice, snowberg



U.S. Gazetteer Counties (2000):

Glacier -- U.S. County in Montana
   Population (2000):    13247
   Housing Units (2000): 5243
   Land area (2000):     2994.717699 sq. miles (7756.282905 sq. km)
   Water area (2000):    42.389528 sq. miles (109.788368 sq. km)
   Total area (2000):    3037.107227 sq. miles (7866.071273 sq. km)
   Located within:       Montana (MT), FIPS 30
   Location:             48.627154 N, 112.810119 W
   Headwords:
    Glacier
    Glacier, MT
    Glacier County
    Glacier County, MT


U.S. Gazetteer Places (2000):

Glacier, WA -- U.S. Census Designated Place in Washington
   Population (2000):    90
   Housing Units (2000): 228
   Land area (2000):     3.007073 sq. miles (7.788284 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    3.007073 sq. miles (7.788284 sq. km)
   FIPS code:            26875
   Located within:       Washington (WA), FIPS 53
   Location:             48.888296 N, 121.933857 W
   ZIP Codes (1990):     98244
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Glacier, WA
    Glacier