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[muh-lib-duh-nuh m] /məˈlɪb də nəm/
noun, Chemistry
a silver-white metallic element, used as an alloy with iron in making hard, high-speed cutting tools. Symbol: Mo; atomic weight: 95.94; atomic number: 42; specific gravity: 10.2.
Origin of molybdenum
1810-20; < New Latin, alteration of earlier molybdēna < Latin molybdaena < Greek molýbdaina galena, equivalent to mólybd(os) lead + -aina suffix of appurtenance Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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British Dictionary definitions for molybdenum


a very hard ductile silvery-white metallic element occurring principally in molybdenite: used mainly in alloys, esp to harden and strengthen steels. Symbol: Mo; atomic no: 42; atomic wt: 95.94; valency: 2–6; relative density: 10.22; melting pt: 2623°C; boiling pt: 4639°C
Word Origin
C19: from New Latin, from Latin molybdaena galena, from Greek molubdaina, from molubdos lead
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for molybdenum

metallic element, 1816, from molybdena, used generally for lead-like minerals, from Greek molybdos "lead," also "black graphite," related to Latin plumbum "lead" (see plumb (n.)), and like it probably borrowed from a lost Mediterranean language, perhaps Iberian. The element so called because of its resemblance to lead ore.

Online Etymology Dictionary, © 2010 Douglas Harper
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molybdenum in Medicine

molybdenum mo·lyb·de·num (mə-lĭb'də-nəm)
Symbol Mo
A hard metallic element that is an essential trace element in plant and animal nutrition. Atomic number 42; atomic weight 95.94; melting point 2,623°C; boiling point 4,639°C; specific gravity 10.22 (at 20°C); valence 2, 3, 4, 5, 6.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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molybdenum in Science
Symbol Mo
A hard, silvery-white metallic element that resists corrosion and retains its strength at high temperatures. It is used to harden and toughen steel and to make high-temperature wiring. Molybdenum is an essential trace element in plant metabolism. Atomic number 42; atomic weight 95.94; melting point 2,617°C; boiling point 4,612°C; specific gravity 10.22 (at 20°C); valence 2, 3, 4, 5, 6. See Periodic Table.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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