addition

noun ad·di·tion \ ə-ˈdi-shən , a- \

Updated on: 20 Apr 2018

Definition of addition

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

— in addition

: ²besides, also

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

— in addition to

: combined or associated with : ¹besides 2

In addition to soup, several salads were served.

See addition defined for English-language learners

See addition defined for kids

Examples of addition in a Sentence

The children learned addition and subtraction.
The museum's collection includes several new additions.

Recent Examples of addition from the Web

The price tag for that last major addition to the museum’s physical plant was $283 million.

— steve johnson, chicagotribune.com, "Art Institute lands largest cash donation, $70 million in total," 17 Apr. 2018
Experimental graphics used last year to depict arrival times for dangerous winds will also become a permanent addition to forecasts.

— Sun-Sentinel.com, "Hurricane forecasters 'cone of uncertainty' is shrinking," 17 Apr. 2018
At the same time, the judge has a tough reputation and may end up a fitting addition to a courtroom cast that involves some of New York's most outspoken figures.

— adam shaw, Fox News, "Who is Kimba Wood? Judge on Cohen case officiated Soros wedding, was Clinton AG pick," 17 Apr. 2018
Since confirming the pregnancy last fall, Zoo staff had been hard at work preparing for the important addition to a species whose wild population has decreased by about 60 percent over the past quarter-century, due to disease and poaching.

— adam cohen, Smithsonian, "First Infant Gorilla Born at the Zoo in Nine Years; Watch a Video of the Birth," 17 Apr. 2018
Players and coaches scroll and swipe away on the bench, looking for instant replay and fast feedback on their iPads, a recent addition to many NHL teams' in-game processes.

— alex prewitt, SI.com, "For NHL Teams and Players, iPads Have Become an Important Part of the Game," 17 Apr. 2018
The four-story addition will be located at the corner of Jefferson Street and Avenue B, across the street from the main hospital building.

— john sowell, idahostatesman, "St. Luke’s Downtown expansion enters a new phase. What’s coming next, and after that | Idaho Statesman," 17 Apr. 2018
The Stelvio launched last year, adding a crucial SUV addition to a lineup anchored previously by the Giulia sedan.

— eric d. lawrence, Detroit Free Press, "Recall issued for 2018 Alfa Romeo Stelvio: Here's why," 16 Apr. 2018
Before Monday’s game the team was 21-3 since Ilyasova’s addition.

— keith pompey, Philly.com, "No word on Joel Embiid's status for Game 3," 16 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'addition.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of addition

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

NEW! Time Traveler

First Known Use: 14th century

in the meaning defined at sense 1

See Words from the same year

addition Synonyms

Other Building Terms

batten, cistern, hearth, lath, transom, wainscot

ADDITION Defined for English Language Learners

addition

noun

Definition of addition for English Language Learners

: the act or process of joining something to something else : the act or process of adding something
mathematics : the act or process of adding numbers
: something or someone more that is included : something or someone that is added