Dic"tion*a*ry (?), n.; pl. Dictionaries (#). [Cf. F. dictionnaire. See Diction.]
1.
A book containing the words of a language, arranged alphabetically, with explanations of their meanings; a lexicon; a vocabulary; a wordbook.
I applied myself to the perusal of our writers; and noting whatever might be of use to ascertain or illustrate any word or phrase, accumulated in time the materials of a dictionary.
Johnson.
2.
Hence, a book containing the words belonging to any system or province of knowledge, arranged alphabetically; as, a dictionary of medicine or of botany; a biographical dictionary.
© Webster 1913.