addition

noun

ad·​di·​tion ə-ˈdi-shən 

a-

1

: a part added (as to a building or residential section)

The addition expanded the kitchen.

2

: anything or anyone added : increase

The clerk was a recent addition to the staff.

3

: the act or process of adding

a recipe enhanced by the addition of freshly ground pepper

especially : the operation of combining numbers so as to obtain an equivalent simple quantity

schoolchildren learning about addition and subtraction

4

: direct chemical combination of substances into a single product

Phrases

in addition

: besides entry 2, also

The job requires a college degree and, in addition, at least two years of experience.

in addition to

: combined or associated with : besides entry 1 sense 2

In addition to soup, several salads were served.

Synonyms

• annex
• extension
• penthouse

Examples of addition in a Sentence

The children learned addition and subtraction.

The museum's collection includes several new additions.

Recent Examples on the Web

With the free agency market also having slim pickings in March, in addition to the the Titans, Browns, and Giants, the Las Vegas Raiders, New Orleans Saints and even possibly the Indianapolis Colts are left in a difficult situation in evaluating the risk on these players. —David Faris, Newsweek, 3 Feb. 2025

The trade picture just gets a little skewed by the Dallas Mavericks getting only one first-round pick for Luka Dončić in addition to 31-year-old All-NBA big man Anthony Davis. —Zach Harper, The Athletic, 3 Feb. 2025

Lamar had lost both song and record of the year three times at previous Grammy ceremonies, in addition to four losses for album of the year (plus two more as a featured artist on albums by others). —Joe Coscarelli, New York Times, 3 Feb. 2025

In addition to her tour news, Beyoncé — who was named Billboard’s Greatest Pop Star of the 21st Century in 2024 — is dominating the 2025 Grammy nominations with 11 nods. —Mitchell Peters, Billboard, 2 Feb. 2025

Word History

Etymology

Middle English addicioun, borrowed from Anglo-French addicion, borrowed from Latin additiōn-, additiō, from addi-, variant stem of addere "to add" + -tiōn-, -tiō, suffix of action nouns

First Known Use

14th century, in the meaning defined at sense 1

Kids Definition

addition

noun

ad·​di·​tion ə-ˈdish-ən 

a-

1

: the result of adding : increase

2

: the act, process, or operation of adding

3

: a part added (as to a building)