Dictionary.com
Thesaurus.com
Synonyms

app

1 American  
[ap] / æp /

noun

  1. Digital Technology. a software application, often a small, specialized program for mobile devices.

    You’ll find numerous free photo editing apps in the app store on your smartphone.

    The word processing app that comes with the laptop isn’t adequate for our publishing needs.

  2. an application; a form to be filled out by an applicant.

    I'm working on my college apps.
app 2 American  
[ap] / æp /

noun

  1. Informal. an appetizer served before a meal.

app. 3 American  

abbreviation

  1. apparatus.

  2. apparent.

  3. appendix.

  4. applied.

  5. appointed.

  6. approved.

  7. approximate.

app British  
/ æp /

noun

  1. informal computing short for application program

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of app1

First recorded in 1985–90; shortening of application ( def. )

Origin of app2

By shortening

Explanation

An app is a program that's designed to be used on your computer, tablet, or mobile phone. If you don't have a weather app, how will you know whether or not to bring your raincoat? App is short for application. You can use it for any kind of computer application (like word processing or spreadsheets), but it usually refers to smartphones. If you have one, you've also got apps, for things like maps, banking, entertainment, to-do lists, and photo editing. Every so often, you'll also hear someone use app as shorthand for a restaurant appetizer: "I'd like to order some apps for the table, when you have a sec!"

Keep Reading on Vocabulary.com

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Find insight on Amazon’s new drug-discovery app, Johnson & Johnson, Monash IVF and GSK in the latest Market Talks covering Health Care.

From The Wall Street Journal • Apr. 15, 2026

Digital tickets for recent Olympics have been distributed through an app and when they hit your account, you can send them to friends and family using their email addresses/Olympic account information.

From Los Angeles Times • Apr. 15, 2026

Guards communicated via the Viber messaging app, with a coded phrase to signal plans for a pushback: "X persons to the operation by Special Team", according to the testimonies.

From BBC • Apr. 14, 2026

OpenAI’s ChatGPT, launched in October of 2022, reached 100 million users by the following January, making it the fastest-growing app of all time.

From Barron's • Apr. 14, 2026

I click the backward arrow in my messaging app and scroll down to my conversation with her.

From "The Sea in Winter" by Christine Day

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.