[ad-on, -awn]


a device or unit added to equipment or a construction: an add-on to a computer; a nice add-on to an old house.
an extra charge: Add-ons for taxes and tour guide fees boosted the price of the vacation to $2,500.
an additional item, as a rider or provision: This is just another legislative add-on.
anything added on: a hi-fi system that can be augmented with add-ons like extra speakers.


being installed or provided as an add-on: an add-on speaker system.

Origin of add-on

First recorded in 1945–50; noun and adj. use of verb phrase add on Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for add-on

Contemporary Examples of add-on

  • I once showed up to read and had been warned that a debut writer was also reading that night—a last minute add-on.

    The Daily Beast logo
    How I Write: Julianna Baggott

    Noah Charney

    February 12, 2014

  • Unlike a phone, wearable technology is an add-on, an accessory, something that comes on top.

  • As a result, it felt like an add-on, meant to artificially moisten another otherwise dry address.

    The Daily Beast logo
    The Opposite of Rousing

    Peter Beinart

    December 2, 2009

British Dictionary definitions for add-on



a feature that can be added to a standard model or package to give increased benefits
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

Word Origin and History for add-on

"additional component," 1941, from add (v.) + on.

Online Etymology Dictionary, © 2010 Douglas Harper