The Collaborative International Dictionary of English v.0.48:

Volcano \Vol*ca"no\, n.; pl. Volcanoes. [It. volcano, vulcano,
   fr. L. Vulcanus Vulkan, the god of fire. See Vulkan.]
   (Geol.)
   A mountain or hill, usually more or less conical in form,
   from which lava, cinders, steam, sulphur gases, and the like,
   are ejected; -- often popularly called a burning mountain.
   [1913 Webster]

   Note: Volcanoes include many of the most conspicuous and
         lofty mountains of the earth, as Mt. Vesuvius in Italy
         (4,000 ft. high), Mt. Loa in Hawaii (14,000 ft.),
         Cotopaxi in South America (nearly 20,000 ft.), which
         are examples of active volcanoes. The crater of a
         volcano is usually a pit-shaped cavity, often of great
         size. The summit crater of Mt. Loa has a maximum length
         of 13,000 ft., and a depth of nearly 800 feet. Beside
         the chief crater, a volcano may have a number of
         subordinate craters.
         [1913 Webster]

WordNet (r) 3.0 (2006):

volcano
    n 1: a fissure in the earth's crust (or in the surface of some
         other planet) through which molten lava and gases erupt
         [syn: vent, volcano]
    2: a mountain formed by volcanic material

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "volcano":
   belch, burst, cascade, debouchment, dissiliency, eructation,
   eruption, flare-up, gush, jet, outbreak, outburst, rapids, rush,
   spate, spew, spurt, torrent, volcan



U.S. Gazetteer Places (2000):

Volcano, HI -- U.S. Census Designated Place in Hawaii
   Population (2000):    2231
   Housing Units (2000): 1229
   Land area (2000):     56.679805 sq. miles (146.800015 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    56.679805 sq. miles (146.800015 sq. km)
   FIPS code:            72350
   Located within:       Hawaii (HI), FIPS 15
   Location:             19.449831 N, 155.235493 W
   ZIP Codes (1990):     96785
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Volcano, HI
    Volcano