English

Noun

bolt-on ‎(plural bolt-ons)

1. an additional service or functionality for a mobile telephone subscription

Adjective

bolt-on ‎(not comparable)

1. (computing) Used to extend an existing system, operating as a plug-in or add-on.
   • 1990, InfoWorld (volume 12, number 39, page 63)

     This week we take a close look at four top contenders in the multitasking arena […] Other bolt-on multitaskers for PCs not included in this comparison include VM/386, Omniview, and Double DOS.