A part that is added to something to enlarge or prolong it; a continuation

• - the railroad's southern extension

A room or set of rooms added to an existing building

The action or process of becoming or making something larger

• - the extension of the president's powers

An application of an existing system or activity to a new area

• - direct marketing is an extension of telephone selling

An increase in the length of time given to someone to hold office, complete a project, or fulfill an obligation

An optional suffix to a file name, typically consisting of a period followed by several characters, indicating the file's content or function

A length of electric cord that permits the use of an appliance at some distance from a fixed socket

An extra telephone on the same line as the main one

A subsidiary telephone in a set of offices or similar building, on a line leading from the main switchboard but having its own additional number

Instruction by a university or college for students who do not attend full time

• - extension courses

Lengths of real or artificial hair woven into a person's own hair to create a long hairstyle

The action of moving a limb from a bent to a straight position

• - seizures with sudden rigid extension of the limbs

The muscle action controlling this

• - triceps extension

The ability of a dancer to raise one leg above the waist, or an instance of this

• - she has amazing extension

• - he could perform 180-degree extensions

The application of traction to a fractured or dislocated limb or to an injured or diseased spinal column to restore it to its normal position

The lengthening of a horse's stride within a particular gait

The range of a term or concept as measured by the objects that it denotes or contains, as opposed to its internal content

The property of occupying space; spatial magnitude

• - nature, for Descartes, was pure extension in space