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Webster 1913 Edition

Noun.

[NL. So named from

Philippe

Plantamour, of Geneva, Switzerland.]

(Chem.)

A rare and doubtful metallic element said to have been discovered in the mineral samarskite.

philippium ‎(uncountable)

(chemistry, obsolete) A supposed metallic element obtainable from samarskite, later discovered to be a mixture of yttrium and terbium.