The Collaborative International Dictionary of English v.0.48:

Bismuth \Bis"muth\, n. [Ger. bismuth, wismuth: cf. F. bismuth.]
   (Chem.)
   One of the elements; a metal of a reddish white color,
   crystallizing in rhombohedrons. It is somewhat harder than
   lead, and rather brittle; masses show broad cleavage surfaces
   when broken across. It melts at 507[deg] Fahr., being easily
   fused in the flame of a candle. It is found in a native
   state, and as a constituent of some minerals. Specific
   gravity 9.8. Atomic weight 207.5. Symbol Bi.
   [1913 Webster]

   Note: Chemically, bismuth (with arsenic and antimony is
         intermediate between the metals and nonmetals; it is
         used in thermo-electric piles, and as an alloy with
         lead and tin in the fusible alloy or metal. Bismuth is
         the most diamagnetic substance known.
         [1913 Webster]

   Bismuth glance, bismuth sulphide; bismuthinite.

   Bismuth ocher, a native bismuth oxide; bismite.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bismuth
    n 1: a heavy brittle diamagnetic trivalent metallic element
         (resembles arsenic and antimony chemically); usually
         recovered as a by-product from ores of other metals [syn:
         bismuth, Bi, atomic number 83]

The Elements (07Nov00):

bismuth
Symbol: Bi
Atomic number: 83
Atomic weight: 208.980
White crystalline metal with a pink tinge, belongs to group 15. Most
diamagnetic of all metals and has the lowest thermal conductivity of all
the elements except mercury. Lead-free bismuth compounds are used in
cosmetics and medical procedures. Burns in the air and produces a blue
flame. In 1753, C.G. Junine first demonstrated that it was different
from
lead.