An attempt to retrieve data.
"I'll look up the train schedule on my phone before we head to the station."
In plain English: A lookup is when you search for specific information inside a list or database to find what you need.
"The lookup in our database system took less than a second."
Usage: Use lookup as a noun when referring to the specific action or process of searching for information in a database or reference source. It describes the attempt to retrieve data rather than the result itself or the act of looking up someone personally.
Misspelling of look up.
"I made a typo and accidentally wrote lookup instead of looking up the word in the dictionary."
In plain English: To look up something means to search for information about it quickly, usually by checking a reference source or using a tool.
"She looked up the definition of the new word in her dictionary."
Usage: Use "lookup" only when referring to the specific action of searching for information in a database or directory, where it functions as a single compound word. In all other everyday contexts involving checking something out or consulting a reference book, you must write it as two separate words: "look up."
The word lookup is a compound formed from the verb phrase look up, which originally meant to search for information by consulting a reference source like a dictionary or index. It entered common usage as a single noun and verb to describe this specific action of retrieving data.