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noun ad·di·tion \ə-ˈdi-shən, a-\

Simple Definition of addition

  • : 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

Source: Merriam-Webster's Learner's Dictionary

Full Definition of addition

  1. 1 :  a part added (as to a building or residential section)

  2. 2 :  the result of adding :  increase

  3. 3 :  the act or process of adding; especially :  the operation of combining numbers so as to obtain an equivalent simple quantity

  4. 4 :  direct chemical combination of substances into a single product

in addition

in addition to

  1. :  combined or associated with :  1besides 2

Examples of addition in a sentence

  1. The children learned addition and subtraction.

  2. The museum's collection includes several new additions.

Origin and Etymology of addition

addicion Anglo-French, from Latin addition-, additio, from addere

First Known Use: 14th century

Other Building Terms

ADDITION Defined for Kids


noun ad·di·tion \ə-ˈdi-shən\

Definition of addition for Students

  1. 1 :  the act or process of adding numbers to obtain their sum

  2. 2 :  something added <an addition to a house>

in addition

  1. :  as something more

in addition to

  1. :  along with or together with <There was ice cream in addition to cake and pie.>

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