encyclopaedias

noun

1. 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.

   “His life's work was a four-volume encyclopedia of aviation topics.”

2. 2

   The circle of arts and sciences; a comprehensive summary of knowledge, or of a branch of knowledge.