Introduction - School Encyclopedia of OXFORD

The word ''encyclopedia", is Greek word and it means,  freely translated "comprehensive education", descends from a phrase that involved coming to grips with the contents of such books. The Greek phrase is enkuklios paideia, made up of enkuklios, "cyclical, periodic, ordinary," and paideia, "education," and meaning "general education." Copyists of Latin manuscripts took this phrase to be a single Greek word, enkuklopaedia, with the same meaning, and this spurious Greek word became the New Latin word encyclopaedia, coming into English with the sense "general course of instruction," first recorded in 1531. In New Latin the word was chosen as the title of a reference work covering all knowledge. The first such use in English is recorded in 1644.