Main Entry: en·cy·clo·pe·dia

Etymology: Medieval Latin encyclopaedia course of general education, from Greek enkyklios + paideia education, child rearing, from paid-, pais child – more at FEW
Date: 1644
: a work that contains information on all branches of knowledge or treats comprehensively a particular branch of knowledge usually in articles arranged alphabetically often by subject

Main Entry: lex·i·con

Inflected Form(s): plural lex·i·ca /-k&/; or lexicons
Etymology: Late Greek lexikon, from neuter of lexikos of words, from Greek lexis word, speech, from legein to say – more at LEGEND
Date: 1603
1 : a book containing an alphabetical arrangement of the words in a language and their definitions : DICTIONARY
2 a : the vocabulary of a language, an individual speaker or group of speakers, or a subject b : the total stock of morphemes in a language
3 : REPERTOIRE, INVENTORY