To look up something (or look something up) is to try and find a piece of information in a book (such as a dictionary, directory, thesaurus or encyclopedia); or by using a computer.
Examples of use:
1. I’m looking up information about grasshoppers.
2. Look up the meaning of new English words in your dictionary.
3. I looked up her telephone number in the telephone directory.
4. Q. What are you doing at the computer?
A. I’m looking up the population of Brazil for my geography project.
||look up and looks up|
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