add-on

American  

[ad-on, -awn] / ˈædˌɒn, -ˌɔn /

noun

1. a device or unit added to equipment or a construction.

   an add-on to a computer;

   a nice add-on to an old house.

2. an extra charge.

   Add-ons for taxes and tour guide fees boosted the price of the vacation to $2,500.

3. an additional item, as a rider or provision.

   This is just another legislative add-on.

4. anything added on.

   Our sable faux fur vest is an easy add-on for dressy or casual occasions.

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adjective

1. being installed or provided as an add-on.

   Add-on packs for this game are just a few dollars.

add-on British  

noun

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

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Etymology

Origin of add-on

First recorded in 1945–50; noun and adj. use of verb phrase add on

Example Sentences

Recurrent consumer spending on digital items, such as in-game microtransactions and add-on content, climbed 12% and now accounts for 81% of all revenue.

From The Wall Street Journal • May 21, 2026

If they had bought an add-on then that cost would have been covered.

From BBC • May 10, 2026

The invite-only program costs $800 a month and is only available as an add-on to existing Vivrelle memberships, which start at $139 a month.

From The Wall Street Journal • Apr. 30, 2026

‘What’s going to be next? An add-on for access to the bathroom?’

From MarketWatch • Apr. 10, 2026

“Two bedroom cape with add-on potential. Nu to market, builder’s special. Contemporary ranch with extras galore.”

From "Typical American" by Gish Jen

Related Words

• preservative
• supplement