An encyclopedia is a book or set of books in which facts about many different subjects or about one particular subject are arranged for reference, usually in alphabetical order.
encyclopedia in British English
or encyclopaedia (ɛnˌsaɪkləʊˈpiːdɪə)
noun
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
Word origin
C16: from New Latin encyclopaedia, erroneously for Greek enkuklios paideia general education, from enkuklios general (see encyclical), + paideia education, from pais child
encyclopedia in American English
(ɛnˌsaɪkləˈpidiə; ɪnˌsaɪkləˈpidiə) or enˌcycloˈpaedia (ɛnˌsaɪkləˈpidiə; ɪnˌsaɪkləˈpidiə)
noun
1.
a book or set of books giving information on all or many branches of knowledge, generally in articles alphabetically arranged
2.
a similar work giving information in a particular field of knowledge
an encyclopedia of philosophy
Word origin
ModL (1508) encyclopaedia < Gr enkyklopaideia, false reading for enkyklios paideia, instruction in the circle of the arts and sciences < enkyklios (en-, in + kyklos, a circle: see cycle) in a circle, general + paideia, education < paideuein, to educate, bring up a child < pais (gen. paidos), child: see pedo-1