Meaning

noun a language user's knowledge of words

noun a reference book containing an alphabetical list of words with information about them

originThrough Middle French or directly from New Latin lexicon, from Byzantine Greek λεξικόν (lexikón, “a lexicon, a dictionary”), ellipsis from Ancient Greek λεξικὸν βιβλίον (lexikòn biblíon, literally “a book of words”), from λεξικός (lexikós, “of words”), from λέξις (léxis, “a saying, speech, word”), from λέγω (légō, “to speak”), ultimately from Proto-Indo-European *leǵ- (“to gather, collect”).…

Etymology from Wiktionary, CC BY-SA 3.0