encyclopaedia

noun3

1. •
   A comprehensive reference work (often spanning several printed volumes) with articles (usually arranged in alphabetical order, or sometimes arranged by category) on a range of subjects, sometimes general, sometimes limited to a particular field.

   • I only use the library for the encyclopedia, as we’ve got most other books here.
   • My old encyclopedia has been gathering dust on the shelf for the past decade.
2. •
   Similarly comprehensive works in other formats.

   • Wikipedia is an online encyclopedia that anyone can edit.
   • The ancient Mesopotamians never got to write an encyclopedia on stone.
3. •
   The circle of arts and sciences (see Etymology); a comprehensive summary of knowledge, or of a branch thereof.

   • His life's work is a four-volume encyclopedia of aviation topics.
   • I have no idea how to build this model railroad, so I'm gonna look it up on Trainpedia, the encyclopedia for all things model train.