Character Dictionary
Kanji Dictionary
noun
Letter rules can be found in a character dictionary. In Japanese, one kanji "letter" or "character" can hold a lot of information, so you have dictionaries dedicated to kanji meanings. That's what this is.
This word is a little old-fashioned these days, so you might also see 漢字辞典 used for a character dictionary. (You'll learn 辞典 soon, if you haven't already!)
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
漢字字典
kanji dictionary
漢和字典
kanji and kanji compound dictionary with Japanese definitions
英和字典
English-Japanese dictionary
え、明日のテスト、字典使ってOKなの？
Oh, are dictionaries OK for tomorrow's test?
私は古代文字字典を読むのが大好きです。
I love reading ancient character dictionaries.
この国字字典はあそこの古本屋で買ったんです。
I bought this Japanese-origin kanji dictionary at that secondhand bookstore over there.