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• deep web
  deep web

  noun

  the portion of the internet that is hidden from conventional search engines, as by encryption; the aggregate of unindexed websites.
• deep Web
  deep Web

  noun

  computing the part of the World Wide Web not accessible through conventional search engines

deep web

American  

[deep web] / ˈdip ˈwɛb /

Or Deep Web

noun

1. the portion of the internet that is hidden from conventional search engines, as by encryption; the aggregate of unindexed websites.

   private databases and other unlinked content on the deep web.

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deep Web British  

noun

1. computing the part of the World Wide Web not accessible through conventional search engines

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Etymology

Origin of deep web

First recorded in 2000–05

Example Sentences

The success of liver treatment eventually led scientists to isolate the deep red compound now known as vitamin B12, or cobalamin.

From Science Daily • Jun. 25, 2026

Posting a photo of the designs they have selected, Lorenze revealed a mix of red and blue paint shades, as well as white fabrics patterned with deep red and blue flowers.

From MarketWatch • Apr. 8, 2026

They have won pretty much everywhere with a wide range of candidates—in special elections and regular elections in deep red territory and in more contested geographies, running candidates of the far left and the center-left.

From The Wall Street Journal • Apr. 6, 2026

The Behn campaign also was canvassing in deep red Williamson County, a prosperous jurisdiction which has become the bedrock of the modern Republican Party.

From Slate • Dec. 2, 2025

The eastern horizon was glowing a deep red when the last snowflake fell.

From "Healer of the Water Monster" by Brian Young