This is a combination of the word 辞書 "dictionary" and the suffix 〜形 or "form." Put them together and you get dictionary form!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
The dictionary form of ate is eat.
I'm fine with dictionary form, but I have trouble with conjugated form.
Write the dictionary form of this word.