look up查字典的用法為look up in a dictionary。
look up是動詞短語，意思有查找、查閱；探望、拜訪；擡頭。
1、查找、查閱。
When?we're?not?sure?which?word?is?the?right?one?for?a?sentence,?look?it?up?in?a?dictionary.?
如果不確定哪個詞適合某個句子，我們就查字典。
2、好轉、改善。
At last things were beginning to look up.
情況終於開始好轉了。
3、擡頭。
How many times must a man look up?
壹個人要擡多少次頭？
4、探望、拜訪。
I'll try to look him up,ask him a few questions.
我會設法登門拜訪，問他幾個問題。
基本例句：
1、When he looked up she was drifting away.
當他擡起頭時，她已姍姍離去。
2、He lay on his back and looked up at the sky.
他仰臥著觀看天空。
3、He looked up into the judge's face.
他舉目直視審判官的面孔。
4、His wife looked up at him joyfully.
他妻子開心地擡眼望著他。
5、Nevertheless,things are looking up.
不過現在情況正在好轉。