Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “extension”

See all translations

extension

noun uk   /ɪkˈsten.ʃən/ us  

extension noun (REACH)

B2 [C or U] the fact of reaching, stretching, or continuing; the act of adding to something in order to make it bigger or longer: Martin Luther King, Jr, campaigned for the extension of civil rights to (= for them to include) black people. The extension (= increasing) of police powers in the province has been heavily criticized. His report contained serious criticisms of the finance director, and, by extension (= therefore), of the entire board of management. The article is an extension of (= takes )further the ideas Professor Fox developed in an earlier book. I've applied for an extension to my visa (= asked for it to last longer). They are hoping to get an extension of their loan (= to be given a longer period of time in which to pay it back).
More examples

extension noun (BUILDING)

[C] UK ( US addition) a new part added to a house or other building: We're building an extension to/on our house.

extension noun (PHONE)

B2 [C] any of two or more phones in the same house that share the same number, or any of a number of phones connected to a switchboard in a large building such as an office: We have an extension in our bedroom. When you call, ask for extension 3276.

extension noun (COMPUTER)

[C] the last part of the name of a computer file, which comes after a (.), and shows what type of file it is

extension

adjective [only before noun] uk   /ɪkˈsten.ʃən/ us  
intended to support students' learning by making them try different or more difficult things in addition to their basic work: The book includes lesson plans and extension activities. US ( UK extramural) organized by a college or university, etc. for students who are not able to be physically present in class: extension classes/courses
(Definition of extension from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of extension?
Add Cambridge dictionaries to your browser to your website

Definitions of “extension” in other dictionaries

Word of the Day

glacial

made or left by a glacier

Word of the Day

Let’s celebrate! (words and phrases for parties)

by Kate Woodford,
December 17, 2014
​​​ With Christmas and New Year almost upon us, we thought it a good time to look at the language of parties and celebrations. First, let’s start with the word ‘party’ itself. To have or throw a party or, less commonly, to give a party is to arrange a party: We’re having a

Read More 

cinderella surgery noun

December 15, 2014
cosmetic surgery to the feet We have all heard of people having nose jobs, boob jobs and liposuction – but now a new trend growing in popularity in America: Cinderella surgery.

Read More