extension

extension

1. Commerce a delay, esp one agreed by all parties, in the date originally set for payment of a debt or completion of a contract

2. the property of matter by which it occupies space; size

3. Med a steady pull applied to a fractured or dislocated arm or leg to restore it to its normal position

4. 

a. a service by which some of the facilities of an educational establishment, library, etc., are offered to outsiders

b. (as modifier): a university extension course

5. Logic

a. the class of entities to which a given word correctly applies: thus, the extension of satellite of Mars is the set containing only Deimos and Phobos

b. conservative extension a formal theory that includes among its theorems all the theorems of a given theory

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

extension

[ik′sten·chən]

(mathematics)

extension fields

(physiology)

A movement which has the effect of straightening a limb.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

extension

A wing or structure added to an existing building.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

extension

(filename extension)

filename extension.

extension

(programming)

A feature or piece of code which extends a program's functionality, e.g. a plug-in.

This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

extension

(1) See domain extension.

(2) A software add-on. For example, extensions add functionality to Web browsers. See browser extension.

(3) Prior to Mac OS X, an executable module that enhanced the Mac operating system. The Windows counterpart is a "dynamic link library" (see DLL).

(4) Apple enhancements starting with iOS 8 and OS X Version 10.10 that enable apps to share functions in other apps. See "iOS 8" in iOS versions.

(5) A file type that is appended to the end of a file name. All executable programs in the Windows and Mac worlds use extensions: .EXE in Windows; .APP in Mac (see APP file). In the Unix/Linux environment, "executables" do not use an extension, but no matter which environment, "data" files have extensions. For example, a file with a .DOC or .DOCX extension is a Microsoft Word document. A file with a .JPG extension is a JPEG image.

Prior to Windows 95, extensions were limited to three characters. Starting with Windows 95, they can be very large (254-260 characters depending on Windows version); however, they are kept small in practice.

Common Extensions and Exhaustive Lists
In this encyclopedia, more than 500 common file extensions are listed under the terms "extension," followed by their first letter such as extension a, extension b and extension c. However, there are websites that catalog many more, including the most obscure; for example, visit www.filext.com. See Win Show file extensions, dangerous extensions and graphics formats. See also domain extension.

Copyright © 1981-2025 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Extension

 

in metalworking. (1) Hot deformation, in which the length of a billet is increased by decreasing the area of its cross section. Extension is performed on hammers and presses by successive pressings of the billet, with a rotation of 90° after each pressing.

(2) Cold sheet pressing, in which hollow components are made from sheets. Cold extension is used to make bushings, casings for instruments and apparatus, and cans and saucepans. The billet is usually cut from a sheet, with an allowance for diameter, and is pressed into the peripheral area of the matrix. Upon the subsequent movement of the puncheon, the middle, unpressed part of the billet is pressed into the opening in the matrix.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.