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 Steilen, the ReSet slate included John Robinson for highway commissioner, Tami O’Brien for clerk, Sara Palermo for collector and Ken Marcin, Chris Sievers, Don Melody and Keith Gray for trustees. —R. Christian Smith, Chicago Tribune, 27 Feb. 2025

Shifting Consumer Behavior Means Tech Is Essential In addition to wanting the flexibility to shop from anywhere, consumers also demand both quick fulfillment and unique shopping experiences. —Kristjan Vilosius, Forbes, 26 Feb. 2025

In addition to apparel, the yarn is also used in home textiles and automobiles. —Jean E. Palmieri, WWD, 26 Feb. 2025

Stewart was seen as a first-base prospect by some when he was drafted, but he’s grown into his body and has shown improvement at third base and even played some second base in addition to first base. —C. Trent Rosecrans, The Athletic, 26 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

Rhymes for addition

• admission
• ambition
• attrition
• audition
• clinician
• cognition
• coition
• commission
• condition
• contrition
• dentition
• dismission

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)