noun
encyclopedia
in-sigh-kluh-PEE-dee-uh/ɪnˌsaɪkləˈpiːdiə/
A reference work containing articles on many subjects.
The encyclopedia contains articles on everything from insects to astronomy.

Etymology
Latin encyclopaedia denoted general instruction and is thought to reflect a misreading of a Greek phrase for a “circle” of education. That comprehensive scope came to describe a reference work covering many subjects.
In context
he wrote this amazing 37 volume encyclopedia of natural history
More examples
- We look up volcanoes in the encyclopedia.
- The library keeps several encyclopedias near the reference desk.
- This children's encyclopedia explains science in simple language.
Forms
encyclopedia · encyclopedias
encyclopedic adjective — Covering a wide range of knowledge.
Similar words
- compendium
- Usually condenses information rather than providing extensive articles on subjects.
- almanac
- Often organizes facts and statistics by year rather than subject.