encyclopedia

American  

[en-sahy-kluh-pee-dee-uh] / ɛnˌsaɪ kləˈpi di ə /

Sometimes encyclopaedia

noun

1. a book, set of books, optical disc, mobile device, or online informational resource containing articles on various topics, usually in alphabetical arrangement, covering all branches of knowledge or, less commonly, all aspects of one subject.

2. Encyclopedia, the French work edited by Diderot and D'Alembert, published in the 18th century, distinguished by its representation of the views of the Enlightenment.

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encyclopedia British  

/ ɛnˌsaɪkləʊˈpiːdɪə /

noun

1. a book, often in many volumes, containing articles on various topics, often arranged in alphabetical order, dealing either with the whole range of human knowledge or with one particular subject

   a medical encyclopedia

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Etymology

Origin of encyclopedia

First recorded in 1525–35; from New Latin encyclopaedia, from Greek enkyklopaidía, a misreading of enkýklios paideía “circular (i.e., well-rounded) education”; encyclical, pedo- ¹

Example Sentences

As a child, he came across a page in an encyclopedia featuring Neil Armstrong and the picture of an astronaut on the Moon from the 1969 Apollo mission.

From BBC • Apr. 2, 2026

He’s like an encyclopedia when it comes to fashion.

From Los Angeles Times • Feb. 14, 2026

Elon Musk's Grokipedia carries thousands of citations to "questionable" and "problematic" sources, US researchers said Friday, raising doubts about the reliability of the AI-powered encyclopedia as an information tool.

From Barron's • Nov. 14, 2025

When his parents gave him a 10-volume encyclopedia, he read the books so often that he memorized their contents and wore off their covers.

From The Wall Street Journal • Nov. 7, 2025

She put the encyclopedia down and studied the old, wrinkled bills.

From "The Great Gilly Hopkins" by Katherine Paterson