辞書で調べて

look it up in the dictionary

→ 辞書
phrase Uncommon #12,735
look it up in the dictionary The て-form of 調べる, used here to make a casual request or instruction. 辞書で調べます is the polite form meaning “I’ll look it up in the dictionary.”
JA: 分からない漢字は辞書で調べてください。
EN: Please look up any kanji you don't understand in the dictionary.

その単語辞書で調べてごらん

Look up that word in the dictionary.

辞書で調べてごらん

Try looking it up in the dictionary.

その単語自分で辞書で調べてごらん

Try looking up that word in the dictionary yourself.

いいえ、でも辞書で調べてみましょう

No, but let’s look it up in the dictionary.

それを辞書で調べてみなさい

Look it up in the dictionary.

分からない単語辞書で調べて

Look up any words you don't know in the dictionary.

辞書で調べてみる

I'll look it up in the dictionary.