1. An electronic dictionary device comprising: a display module including a first and a second display screen; a dictionary storage module which stores dictionary data that causes a plurality of entry words including compound words obtained by connecting a plurality of words to correspond to explanatory information on the entry words; and a processor which implements processes comprising: a common word list display process of retrieving entry words for compound words from the entry words in the dictionary data stored in the dictionary storage module, listing words common to the retrieved compound words, and displaying the listed words on the first display screen; a compound word list display process of reading, from the dictionary data, entry words for compound words connecting with a word specified by a user operation in a list displayed by the common word list display process, and displaying the entry words for the compound words connecting with the word specified by the user operation in list form on the second display screen; and an explanatory information display process of reading a corresponding piece of explanatory information from the dictionary data when a compound word has been specified according to a user operation in a compound word list displayed by the compound word list display process, and displaying the corresponding piece of explanatory information on the second display screen.