Definition of lookup

Short definition: The phrase look up means trying to find information, such as a word, fact, or number, in a book or online, and it can also mean lifting your eyes to see something higher than where you are.

Looking for a clear and natural explanation of the word lookup? The word lookup is very common in modern English, especially in learning, technology, and daily problem solving. People use it when they need to find information, check facts, or search for details in a dictionary, database, or online. Sometimes it works as a verb phrase, and sometimes it appears as a noun in technical or learning contexts. Below, each meaning is explained in a calm and natural way, so it feels human, practical, and easy to understand.

lookup v., n. /ˈlʊkˌʌp/

Forms: look up, looks up, looked up, looking up, lookup
Related: search v., check v., reference n.
Syllable: look-up

  1. (Verb) To search for information in a book website or other source because you need to know something.

    To look up means to find information by searching for it in a dictionary, on the internet, in a database, or in another reference source when you do not already know the answer.

    When she did not understand the word, she decided to look it up in the dictionary before continuing to read.
    He quickly looked up the restaurant online to check its opening hours and customer reviews.
    If you are unsure about the rule, it is always better to look up the correct information instead of guessing.

    Synonyms: search for, check, find, research, look for, reference, verify, consult, seek information, investigate, read up on, check out
    Antonyms: guess, assume, ignore, overlook, skip checking, make up, forget, avoid researching, neglect, misremember, invent, estimate

  2. (Verb) To visit or contact someone, often unexpectedly or after some time.

    To look up someone can mean visiting them or contacting them, especially when you have not seen them in a long time and want to reconnect.

    When he traveled back to his hometown, he decided to look up an old friend he had not seen for years.
    She promised to look him up the next time she visited the city.
    If you are ever in town, look me up and we can catch up properly.

    Synonyms: visit, contact, drop by, check in on, reconnect with, meet up with, reach out to, call on, see again, get in touch, find and visit, come by
    Antonyms: avoid, ignore, stay away, lose contact, forget, cut off, disconnect, neglect, pass by, miss, leave alone, keep distance

  3. (Noun) The act of searching for information or the result of that search.

    A lookup refers to the act of searching for information or the data that is found, commonly used in learning, programming, and data related situations.

    The app performs a quick lookup to show definitions instantly when you tap on a word.
    In the system, each user ID triggers a database lookup to retrieve the correct profile information.
    That table allows fast lookups without loading the entire dataset.

    Synonyms: search, query, check, reference action, data retrieval, information search, scan, database query, fact check, info pull, data fetch, reference lookup
    Antonyms: guess, assumption, random answer, no search, blind guess, unverified info, skipped check, ignored data, rough estimate, speculation, invented detail, unchecked claim

  4. (Slang) A casual way to say finding something out quickly.

    In casual conversation, people say lookup or look it up to mean quickly checking something, often on a phone, without making it sound formal or serious.

    I’m not sure about the score, let me do a quick lookup on my phone.
    He laughed and said he would just look it up instead of arguing about the fact.
    She did a fast lookup to settle the debate in the group chat.

    Synonyms: quick check, fast search, phone check, instant search, quick verify, rapid lookup, fast reference, quick find, casual search, easy check, light research, simple check
    Antonyms: long research, deep study, ignore, avoid checking, guess, overthink, delay, postpone search, skip verifying, forget to check, leave unknown, stay unsure

Conversation Using the Phrase Look Up

The following conversation takes place between two students working on an assignment. It shows how the phrase look up is used naturally when people talk about studying, finding information, and solving problems together.

Anna: Do you know what this word means? I keep seeing it in the article.

Mark: I am not sure either, but we can look it up instead of guessing.

Anna: Good idea, I will look up the meaning online so we understand the sentence properly.

Mark: While you do that, I will look up some background information about the topic.

Anna: Okay, I found it, and it makes a lot more sense now.

Mark: See, taking a moment to look things up really saves time later.

Anna: Yeah, and it helps us avoid misunderstandings when we write our answers.

Mark: Exactly, looking things up is a good habit for learning.

Phrases Containing the Words Look Up

The phrases below show how look up is commonly used in everyday English, especially when talking about learning, searching for information, and noticing things.

Look up a word

To find a word’s meaning.

When she reads something confusing, she always looks up a word in the dictionary to understand the sentence better.

Look up information

To search for facts.

He looked up information online before making a decision so he would not rely only on guesses.

Look up the meaning

To find what something means.

If you are not sure about the phrase, just look up the meaning instead of ignoring it.

Look up online

To search using the internet.

She quickly looked up the address online to make sure they were going to the right place.

Look up numbers

To search for contact details.

He looked up numbers in his phone to call an old friend from school.

Look up a name

To find details about a person.

She looked up his name because it sounded familiar and she wanted to remember where she knew him from.

Look up directions

To find how to get somewhere.

Before leaving the house, they looked up directions so they would not get lost.

Look up facts

To check correct information.

He likes to look up facts instead of believing everything he hears.

Look up at the sky

To raise your eyes upward.

She stopped walking and looked up at the sky to watch the clouds slowly move.

Look up from your phone

To stop staring downward.

He finally looked up from his phone and noticed everyone waiting for him.

Look up old records

To search past information.

The researcher looked up old records to understand what happened years ago.

Look up the answer

To search for a solution.

If you are stuck, you can look up the answer and then try to understand it.

Look up later

To search at another time.

She saved the question so she could look it up later when she had more time.

Look up in a dictionary

To search using a dictionary.

Teachers often tell students to look up words in a dictionary instead of guessing.

Look up details

To find specific information.

He looked up details about the event before deciding to attend.

Look up someone online

To search for a person on the internet.

She looked up someone online after receiving a message from an unfamiliar name.

Look up prices

To check costs.

They looked up prices to compare different options before buying anything.

Look up a place

To find information about a location.

He looked up the place to see photos and reviews before visiting.

Look up instructions

To find how something works.

She looked up instructions online because the manual was missing.

Look up quickly

To search fast.

He looked up the answer quickly so the conversation could continue smoothly.

Words Rhyme with lookup

cup
pup
sup
yup
clup
makeup
wakeup
shakeup
breakup
backup
checkup
pickup
hiccup
lockup
mockup
setup
getup
letup
flare-up
grown-up
close-up
buttercup
ketchup
linkup
wrap-up
sum-up
step-up
straight-up
seven-up
chin-up
POS: Verb