add-on

noun

Etymology: Etymology tree English add ondeverb. English add-on Deverbal from add on.

1. Something which can be appended to something else.

   “Payments made before an add-on sale must be allocated entirely to the previous contract or contracts.”

2. A software extension or hardware peripheral that provides additional functions or customization for a core application or system.

   “Microdrives that can hold several gigabytes (see Figure 2.20) have been available as add-ons for portable devices.”

3. Additional chips that can be purchased at specific times in tournament play.
4. Synonym of expansion pack.