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English definition of “extension”

extension

noun  /ɪkˈsten·ʃən/ us  

extension noun (PHONE)

[C] (abbreviation ext.) any of two or more telephones in the same house that share the same number: We have an extension in our bedroom. [C] (abbreviation ext.) An extension is also any of the telephones connected to a central system, esp. in a business.

extension noun (ADDITION)

[C/U] an amount by which something is increased, or something added to something else: a contract extension I applied for an extension to my visa. [C] We’re building an extension on our house to enlarge the kitchen.
(Definition of extension from the Cambridge Academic Content Dictionary © Cambridge University Press)
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