Detail of OED - dictionary
See OED entry for Dictionary

The fact that the first English citation for this word dates from 1526 is a reminder that dictionaries have only been around for a relatively short period. The OED definition shows that the conventions for this type of book took a while to settle down. The quotations outline the types of dictionaries that were produced in the early 1500s, one example being J Withals’ ‘A Short dictionarie for yonge beginners’ (1556), in which words were translated from English to Latin, and were arranged not alphabetically, but under subject-headings such as ‘the names of Byrdes, Byrdes of the Water, Byrdes about the house, as cockes, hennes, etc., of Bees, Flies, and others.’

Note the relatively insulting colloquial phrase associated with the word – ‘to have swallowed the dictionary’, the most recent quote, from 1966, being '‘Put a sock in it!’ ‘'Ev've swallered the dictionary!’'