Dictionary, Lexicon
noun
You need to know the word rules of the language you're learning, don't you? Then you need a good dictionary that can explain its lexicon!
じてん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
辞典の使い方がよく分からないんですが、教えてもらえませんか?
I don't quite understand how to use the dictionary, could you please teach me?
日本語辞典なら、私のデスクの上にありますよ。
If you're looking for a Japanese dictionary, it's on my desk.
電子辞書には色んな辞典が入っています。
An electronic dictionary has various dictionaries in it.