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

In addition to his courtroom work, Dickey has acted as a legal analyst for CNN and other media outlets. —Joseph Epstein, Newsweek, 11 Dec. 2024

In addition to Guerendo, defensive end Nick Bosa (hip/oblique), tackle Trent Williams (heel/ankle) and guard Ben Bartch (ankle) missed practice. —Matt Barrows, The Athletic, 11 Dec. 2024

In addition to his 374 home runs, Colavito drove in 1,159 runs (leading the league with 108 in 1965) and had a .266 career batting average. —Richard Goldstein, New York Times, 11 Dec. 2024

In addition to the fake ID cards, Mangione had a gun and silencer similar to the ones authorities believe the killer used in New York, Tisch said. —Nick Penzenstadler, USA TODAY, 10 Dec. 2024

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)