add on (third-person singular simple present adds on, present participle adding on, simple past and past participle added on)
- (transitive) To incorporate (something extra, often an amount of money) into something else (often a bill).
- (intransitive) To put an expansion onto a building, usually a home.
add on (plural add ons)
- Alternative form of add-on
- The manufacturer sold many add ons for the basic camera.
- The secretary offered a typing and copying service for theses, with the option of binding as an add on.