Extension

ɪkˈstɛnʃən

nounBeginnerVery CommonGeneral

Definitions

4 meanings
1

An added part that increases the size, length, or duration of something.

ɪkˈstɛnʃən

nounneutralBeginner
General

A part that is added to something to enlarge or prolong it.

The library is planning an extension to its reading room.

💡 Simply: Imagine your house is too small. An extension is like adding another room to make it bigger!

👶 For kids: Like adding a long part to something to make it bigger!

More Examples

2

We bought an extension cord to reach the outlet.

3

The company offers a one-month extension on the payment deadline.

How It's Used

Construction

"The house has a new extension added to the back."

Technology

"The software includes a browser extension for easy access."

2

The act of making something longer, larger, or more comprehensive.

ɪkˈstɛnʃən

nounneutralmedium
General

The act of extending something.

The company announced an extension of its product line.

💡 Simply: It's like stretching something out, like extending a deadline so you have more time.

👶 For kids: Making something go longer or bigger.

More Examples

2

The government proposed an extension of the tax breaks.

3

The professor allowed an extension on the essay due date.

How It's Used

Business

"The extension of the loan period was approved."

Law

"The judge granted an extension on the filing deadline."

Tip:Think of the action of extending a hand - it's the extension.
3

A telephone number connected to a main telephone line.

ɪkˈstɛnʃən

nounneutralBeginner
Technology

A telephone number in addition to the main line.

Could you give me the extension for the accounting department?

💡 Simply: It's like a secret phone number within a bigger office phone system. You call an extension to talk to someone specific.

👶 For kids: A special phone number inside a big phone.

More Examples

2

He reached the secretary by dialing her extension.

3

Please enter the extension to reach your party.

How It's Used

Telecommunications

"Please dial extension 123 to reach the sales department."

Business

"I have an extension at the office."

Tip:Like an extra 'branch' off the main phone line, an extension.
4

A software or hardware component that adds additional features or functionality to a program or device.

ɪkˈstɛnʃən

nounneutralBeginner
Technology

A software or hardware add-on.

I installed a Chrome extension to translate web pages.

💡 Simply: Think of a gadget that you can add to your phone, like a cool new camera lens. An extension does something similar for computer programs.

👶 For kids: A new part that makes a computer program do more things.

More Examples

2

This program requires a specific file extension to run correctly.

3

The extension is compatible with multiple browsers

How It's Used

Computer Science

"Install this browser extension to block ads."

Technology

"The extension adds new features."

Tip:Extending a program's capabilities.

Idioms & expressions

by extension

Through a natural or logical consequence; as a result of something else.

"If the policy fails, by extension, so does the administration."

file extension

Suffix to the filename, indicating file type.

"The file has a .docx extension."

From Middle English *extensioun*, from Latin *extensiō* (“a stretching out, enlargement”), from *extendō* (“stretch out, extend”).

The word 'extension' has been used since the 14th century, initially referring to the action of extending something.

Memory tip

Think of extending your arm – it's an extension of your body.

extentionextinsion

Usage

40%Spoken
60%Written