addition

 
Pronunciation: /əˈdɪʃ(ə)n/

noun

[mass noun]
  • 1the action or process of adding something to something else: the hotel has been extended with the addition of more rooms
  • [count noun] a person or thing added or joined: you will find the coat a useful addition to your wardrobe
  • 2the process of calculating the total of two or more numbers or amounts: she began with simple arithmetic, addition and then subtraction
  • Mathematics the process of combining matrices, vectors, or other quantities under specific rules to obtain their sum or resultant: [with modifier]: the concepts of vectors and vector addition

Phrases

in addition

as an extra person or thing: members of the board were paid a small allowance in addition to their normal salary

Origin:

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