SILICON

silicon, Si, atomic number

(noun) 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

Source: WordNet® 3.1

Etymology 1

Noun

silicon (usually uncountable, plural silicons)

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

Synonyms: silicium (obsolete), silicum (obsolete)

(chemistry, countable) A single atom of this element.

Usage notes

Do not confuse silicon with silicone.

Etymology 2

From the silicon chips used in computers

Noun

silicon (uncountable)

(slang) computing

(slang) computer processor

Abbreviation of silicon chip.

Source: Wiktionary

Sil"i*con, n. Etym: [See Silica.] (Chem.)

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition