silicon

n. nonmetallic element which makes up more than one fourth of the earth's crust and is used in the manufacture of metal alloys and electronic components (Chemistry)

Silicon (IPA: or , ) is the chemical element that has the symbol Si and atomic number 14. A tetravalent metalloid, silicon is less reactive than its chemical analog carbon. As the eighth most common element in the universe by mass, silicon occasionally occurs as the pure free element in nature, but is more widely distributed in dusts, planetoids and planets as various forms of silicon dioxide or silicate. On Earth, silicon is the second most abundant element (after oxygen) in the crust, making up 25.7% of the crust by mass.
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Silicon /sil·i·con/ a chemical element, at. no. 14, symbol Si. silicon carbide a compound of silicon and carbon used in dentistry as an abrasive [more]Silicon - Community and Resources

Noun
1. a tetravalent nonmetallic element; next to oxygen it is the most abundant element in the earth's crust; occurs in clay and feldspar and granite and quartz and sand; used as a semiconductor in transistors
(synonym) Si, atomic number 14
(hypernym) chemical element, element
(substance-holonym) silicone, silicone polymer

(n.)
A nonmetalic element analogous to carbon. It always occurs combined in nature, and is artificially obtained in the free state, usually as a dark brown amorphous powder, or as a dark crystalline substance with a meetallic luster. Its oxide is silica, or common quartz, and in this form, or as silicates, it is, next to oxygen, the most abundant element of the earth's crust. Silicon is characteristically the element of the mineral kingdom, as carbon is of the organic world. Symbol Si. Atomic weight 28. Called also silicium.