A region in California to the south of San Francisco that is noted for its concentration of high-technology industries WordNet 3.0 & Open English WordNet

Silicon Valley is a region in Northern California that is a global center for high technology and innovation. Wikipedia

Nickname for the southern portion of the San Francisco Bay Area in the United States. Wikipedia Disambiguation

Subregion of the San Francisco Bay Area known for its concentration of high-technology industry Wikidata

The southern part of the San Francisco Bay Area in northern California, USA, originally referring to the concentration of silicon chip innovators and manufacturers, but eventually becoming a metaphor for the entire concentration of high tech businesses. OmegaWiki

Originally, the region of the San Francisco Bay Area in which there are a high number of industries producing silicon chips; later extended to mean the entire concentration of high-tech businesses in this area. Wiktionary

Nickname for region in San Francisco. Wiktionary (translation)