[əˈdɪʃn], (Noun)

Definitions:
- the action or process of adding something to something else
(e.g: the hotel has been extended with the addition of more rooms)

- the process of calculating the total of two or more numbers or amounts
(e.g: she began with simple arithmetic, addition and then subtraction)


Phrases:
- in addition

Origin:
late Middle English: from Latin additio(n-), from the verb addere (see add)