app

noun [C] /æp/

Definition

› abbreviation for application: a computer program that is designed for a particular purpose: You can run an app on your PC that will find the files and burn them to a CD. › abbreviation for application: a computer program or piece of software designed for a particular purpose that you can download onto a mobile phone or other mobile device: There are apps for everything, from learning a language to booking movie tickets.

(Definition of app noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)