look forward to和look up、look out分别为什么意思

look forward to
期望; 盼望
例句：
I look forward to being alone in the house.
我盼望著能自己一人在这所房子.
look up
查询
例句：
You can look up this word in the vocabulary.
你可以在词汇表里查这个词.
look out
小心; 注意
多用于语气词,例如：
Look out!
小心!
FBI is on the look out for the agent these days.
这些天联邦调查局正在注意那个特工.