add-on

[ad-on, -awn]

See more synonyms for add-on on Thesaurus.com

noun

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.

adjective

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for add-on

supplement, preservative, addition, extra, accompaniment, add-on

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.
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.
Is Wearable Technology a Fad or the Future?
Daniel Gross
January 9, 2014
As a result, it felt like an add-on, meant to artificially moisten another otherwise dry address.
The Opposite of Rousing
Peter Beinart
December 2, 2009

British Dictionary definitions for add-on

add-on

noun

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.