/ Dictionary / Index S Silicon Valley: Meaning and Definition of Find definitions for: Sil'icon Val'ley Pronunciation: [key] the area in northern California, southwest of San Francisco in the Santa Clara valley region, where many of the high-technology design and manufacturing companies in the semiconductor industry are concentrated. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. silicon tetrahydride silicosis Related Content Daily Word Quiz: alacrity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language