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 WordNet 3.0 & Open English WordNet

Silicon is a chemical element with the symbol Si and atomic number 14. Wikipedia

Chemical element with symbol Si and atomic number 14. Wikipedia Disambiguation

Chemical element with symbol Si and atomic number 14 Wikidata

A brittle metalloid element with symbol Si and atomic number 14 that exists in two allotropic forms; occurs principally in sand, quartz, granite, feldspar, and clay. It is usually a grey crystalline solid but is also found as a brown amorphous powder. It is used in transistors, rectifiers, solar cells, and alloys. Its compounds are widely used in glass manufacture, the building industry, and in the form of silicones. OmegaWiki

A nonmetallic element (symbol Si) with an atomic number of 14 and atomic weight of 28.0855. Wiktionary