MOLYBDENUM

n. (Mo) graphite-like mineral of the chromium group used to strengthen and harden steel (Chemistry)

Molybdenum (IPA: , from the Greek meaning "lead-like"), is a chemical element with the symbol Mo and atomic number 42. It has the sixth highest melting point of any element, and for this reason it is often used in high-strength steel alloys. Molybdenum is found in trace amounts in plants and animals, although excess molybdenum can be toxic in some animals. Molybdenum was discovered in 1778 by Carl Wilhelm Scheele and first isolated in 1781 by Peter Jacob Hjelm.
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Molybdenum /mo·lyb·den·um/ a chemical element, at. no. 42. mo·lyb·de·num n. Symbol Mo A hard metallic element that is an essential trace element in [more]Molybdenum - Community and Resources

Noun
1. a polyvalent metallic element that resembles chromium and tungsten in its properties; used to strengthen and harden steel
(synonym) Mo, atomic number 42
(hypernym) metallic element, metal
(substance-holonym) molybdenite

(n.)
A rare element of the chromium group, occurring in nature in the minerals molybdenite and wulfenite, and when reduced obtained as a hard, silver-white, difficulty fusible metal. Symbol Mo. Atomic weight 95.9.