look up

What it means

To search for information in a reference source like a dictionary, book, or website. It's the standard verb for any quick fact-finding action, from checking a word's meaning to finding someone's phone number online.

Examples

• If you don't know that word, just look it up in the dictionary.
• I had to look up the train times before leaving for the station.
• She looked up his number and called him right away.
• Students often look up grammar rules on their phones during class.

Where it comes from

Separable: you can say 'look up the word' or 'look the word up' — but when the object is a pronoun, it MUST go in the middle ('look it up', never 'look up it'). The phrase comes from the literal act of raising your eyes to a list or page when searching.

Related phrasal verbs