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The Collaborative International Dictionary of English v.0.48 (gcide)

Palladium \Pal*la"di*um\ (p[a^]l*l[=a]"d[i^]*[u^]m), n. [L., fr.
Gr. Palla`dion, fr. Palla`s, Palla`dos, Pallas.]
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1. (Gr. Antiq.) Any statue of the goddess Pallas; esp., the
famous statue on the preservation of which depended the
safety of ancient Troy.
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2. Hence: That which affords effectual protection or
security; a safeguard; as, the trial by jury is the
palladium of our civil rights. --Blackstone.
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Palladium \Pal*la"di*um\, n. [NL.] (Chem.)
A rare metallic element of the light platinum group, found
native, and also alloyed with platinum and gold. It is a
silver-white metal resembling platinum, and like it permanent
and untarnished in the air, but is more easily fusible, with
a melting point of 1555[deg] C. It can also be prepared as a
finely divided black powder. It is unique in its power of
absorbing hydrogen, which it does to the extent of nearly a
thousand volumes, forming the alloy {Pd2H}. It is used for
graduated circles and verniers, for plating certain silver
goods, and somewhat in dentistry. It was so named in 1804 by
Wollaston from the asteroid Pallas, which was discovered in
1802. Symbol Pd. Atomic number, 46. Atomic weight, 106.42.
Density 12.0.
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Pd \Pd\ prop. n.
The chemical symbol for {palladium}, an element of the
platinum group, of atomic number 46.

Syn: palladium.
[WordNet 1.5]