(computing) A plug-in.

Alternative form of add-on

Initialism of attention deficit disorder. / Initialism of accidental death and dismemberment.

(law) Abbreviation of addendum.

(radio) The addition of a song to a station's playlist. / (computer science) An act or instance of adding. / (video games) An additional enemy that joins a fight after the primary target.

(sometimes attributive) Something which can be appended to something else.

(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.

to put two things or numbers together (e.g., 2+2)

Third-person singular simple present indicative form of adde

Obsolete spelling of add