Japanese-language dictionary
A dictionary that explains Japanese words in Japanese, as opposed to a bilingual dictionary.
I look up the meaning of a word in a Japanese-language dictionary.
dictionary of a national language
A broader, less common sense referring to a dictionary of any national language, not necessarily Japanese.
This research compares dictionaries of various national languages.
If there's a word you don't understand, look it up in a Japanese dictionary.
I checked the reading of this kanji in a Japanese dictionary.
和英辞典 is a bilingual Japanese-English dictionary, while 国語辞典 explains Japanese words entirely in Japanese.
漢和 (as in 漢和辞典) is a dictionary that explains kanji and kanji compounds in Japanese, while 国語辞典 is a general dictionary of Japanese words.