[ɛkˈstɛnʃn], (Noun)

Definitions:
- a part that is added to something to enlarge or prolong it
(e.g: the railway's southern extension)

- a length of electric cable which permits the use of appliances at some distance from a fixed socket

- a subsidiary telephone on the same line as the main one
(e.g: you can listen on the extension in the bedroom)

- the action of moving a limb from a bent to a straight position
(e.g: seizures with sudden rigid extension of the limbs)

- denoting instruction by a university or college arranged for people who are not full-time students
(e.g: a postgraduate extension course)

- the range of a term or concept as measured by the objects which it denotes or contains

- the property of occupying space
(e.g: nature, for Descartes, was pure extension in space)


Phrases:
- by extension

Origin:
late Middle English: from late Latin extensio(n-), from extendere ‘stretch out’ (see extend)