extension

noun ex·ten·sion \ik-ˈsten(t)-shən\

Definition of EXTENSION

a : the action of extending : state of being extended

b : an enlargement in scope or operation <tools are extensions of human hands>

a : the total range over which something extends : compass

b : denotation 4

a : 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 (as the knee or elbow) that increases the angle between the bones of the limb at the joint — compare flexion 4a

: a property whereby something occupies space

: an increase in length of time; specifically : an increase in time allowed under agreement or concession

: a program that geographically extends the educational resources of an institution by special arrangements (as correspondence courses) to persons otherwise unable to take advantage of such resources

a : 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

: a mathematical set (as a field or group) that includes a given and similar set as a subset

See extension defined for English-language learners

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Origin of EXTENSION

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

First Known Use: 15th century

Related to EXTENSION

Synonyms: drawing out, elongation, lengthening, prolongation, prolonging, stretching

Antonyms: abbreviation, abridgment (or abridgement), curtailment, cutback, shortening

Rhymes with EXTENSION

dimension, high-tension, Vincentian

EXTENSION Defined for Kids

extension

noun ex·ten·sion \ik-ˈsten-shən\

Definition of EXTENSION for Kids

: the act of making something longer or greater <extension of the sail>

: an increase in length or time

: a part forming an addition or enlargement

Medical Dictionary

extension

noun ex·ten·sion \ik-ˈsten-chən\

Medical Definition of EXTENSION

: the stretching of a fractured or dislocated limb so as to restore it to its natural position

: 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 1