TKG English Learner's Dictionary

addition

additionnoun

American /ə.ˈdɪ.ʃən/ British /ə.ˈdɪ.ʃən/ Stress falls on the middle part: uh-DISH-un. The letters ti sound like sh, as in nation.
plural additions
fairly common

An addition is the act of adding, or something that has been added, whether a number, a member of a group, or a part of a building.

  1. adding numbersthe process of putting numbers or amounts together to find a total

    uncountable [U] mathematicseducation

    Collocations

    adjective + noun simple addition, basic addition, mental addition
    verb + noun do addition, practice addition, check your addition

    Antonyms subtraction

  2. thing or person addeda person or thing added to a group, making it larger or better

    countable [C]

    Collocations

    adjective + noun a welcome addition, a valuable addition, a recent addition, the latest addition, a new addition
    noun + preposition addition to

  3. part built onto a buildinga new room or part built onto a building

    countable [C] Americanarchitecture

    Collocations

    verb + noun build an addition, put an addition on the house

Phrases

in addition

used to add another fact or point to what has already been said

in addition to something

as well as something

Word family

Usage

Addition is usually uncountable when it means the math process of adding numbers: some addition, do addition. It can be countable for one problem in a set, as in the first addition was easy, though addition problems is the more natural way to say this. It is always countable when it means a person, thing, or room that has been added: an addition to the team, build an addition.

Common mistakes

She is a new addition in the team. She is a new addition to the team.
addition to something, not in.

For translators

Grammar trap Addition is usually uncountable for the math process (some addition), though a countable use for one problem exists; it is always countable for a person, thing, or room added (an addition to the team, build an addition).
False friends An internationalism spelled like addition in several languages usually keeps the math sense; check whether it also covers a person or thing added, or a room built onto a house.