ex·​ten·​sion | \ ik-ˈsten(t)-shən How to pronounce extension (audio) \

Definition of extension

1a : the action of extending : state of being extended
b : an enlargement in scope or operation tools are extensions of human hands
2a : the total range over which something extends : compass
3a : the stretching of a fractured or dislocated limb so as to restore it to its natural position
b : an unbending movement around a joint in a limb (such as the knee or elbow) that increases the angle between the bones of the limb at the joint — compare flexion sense 4a
4 : a property whereby something occupies space
5 : an increase in length of time specifically : an increase in time allowed under agreement or concession
6 : a program that geographically extends the educational resources of an institution by special arrangements (such as correspondence courses) to persons otherwise unable to take advantage of such resources
7a : a part constituting an addition
b : a section or line segment forming an additional length
c : an extra telephone connected to the principal line
d : a length of natural or synthetic hair that is worn attached to one's natural hair
e : a series of usually three or four characters following a dot at the end of the name of a computer file that specifies the file's format or purpose
8 : a mathematical set (such as a field or group) that includes a given and similar set as a subset

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Examples of extension in a Sentence

extension of the patient's life He's asking for a contract extension. Make sure that the muscles get the proper amount of extension. I missed the deadline but was granted an extension.
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Recent Examples on the Web State Health Officer Scott Harris said the extension was the right thing to do, particularly as students head back to school beginning next week. USA TODAY, "NYC taxis, Fisher Cats, casinos: News from around our 50 states," 31 July 2020 Or did life gain a foothold, even briefly, on at least one other planet and, by extension, perhaps on planets beyond our solar systems? William Harwood, CBS News, "NASA readies launch of Mars rover to look for signs of past life, collect samples for return to Earth," 28 July 2020 The show's six episodes are based on real events that explore Australia's deeply-flawed immigration system—and by, extension, several systems across the world. Christopher Rosa, Glamour, "Netflix's Stateless Is Tough But Necessary Viewing," 8 July 2020 Compensation update: Patrick Mahomes’ 10-year extension is worth $450 million, sources tell ESPN. oregonlive, "Kansas City’s Patrick Mahomes signs richest contract in sports history: Report," 6 July 2020 Randall played so well in 2018 that a potential contract extension was a storyline during the offseason. Scott Patsko, cleveland, "Which offseason departure will the Browns miss most? Cleveland Browns 20 questions for ’20," 1 July 2020 The state’s utility regulatory commission is studying the pandemic impacts to determine if an extension is necessary. Sarah Bowman, The Indianapolis Star, "As the moratorium on utility shutoffs comes to a close, what's next for consumers still uncertain," 24 June 2020 This new extension is only applicable to PPP loans made after June 5, 2020. Tom Cooney And Crystal Faulkner, The Enquirer, "BusinessWise: Paycheck Protection Program Flexibility Act legislation updates," 23 June 2020 Stephens also ruled that the 1945 law did not represent an unconstitutional ceding of powers to the governor by the Legislature, and therefore Whitmer's extension of the state of emergency and use of emergency orders are lawful. Paul Egan, Detroit Free Press, "Federal judge questions Gov. Gretchen Whitmer's coronavirus emergency powers," 19 June 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'extension.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of extension

15th century, in the meaning defined at sense 1a

History and Etymology for extension

Middle English, from Late Latin extension-, extensio, from Latin extendere

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Time Traveler for extension

Time Traveler

The first known use of extension was in the 15th century

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Statistics for extension

Last Updated

6 Aug 2020

Cite this Entry

“Extension.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/extension. Accessed 6 Aug. 2020.

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More Definitions for extension


How to pronounce extension (audio)

English Language Learners Definition of extension

: the act of making something longer or greater
: the act of straightening or stretching something (such as an arm or a leg)
: extra time allowed for doing something


ex·​ten·​sion | \ ik-ˈsten-shən How to pronounce extension (audio) \

Kids Definition of extension

1 : the act of making something longer or greater extension of the sail
2 : an increase in length or time
3 : a part forming an addition or enlargement


ex·​ten·​sion | \ ik-ˈsten-chən How to pronounce extension (audio) \

Medical Definition of extension

1 : the stretching of a fractured or dislocated limb so as to restore it to its natural position
2 : an unbending movement around a joint in a limb (as the knee or elbow) that increases the angle between the bones of the limb at the joint — compare flexion sense 1

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Legal Definition of extension

: an increase in length of time specifically : an increase in the time allowed under an agreement

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