Definition of extension
3 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
4 : a property whereby something occupies space
5 : an increase in length of time; specifically : an increase in time allowed under agreement or concession
6 : 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
7 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
8 : a mathematical set (as a field or group) that includes a given and similar set as a subset
Examples of extension in a sentence
extension of the patient's life
He's asking for a contract extension.
Make sure that the muscles get the proper amount of extension.
I missed the deadline but was granted an extension.
Origin of extension
Middle English, from Late Latin extension-, extensio, from Latin extendere
First Known Use: 15th century
EXTENSION Defined for Kids
Definition of extension for Students
1 : the act of making something longer or greater <extension of the sail>
2 : an increase in length or time
3 : a part forming an addition or enlargement
Medical Definition of extension
1: the stretching of a fractured or dislocated limb so as to restore it to its natural position
2: 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
Legal Definition of extension
: an increase in length of time; specifically : an increase in the time allowed under an agreement
Learn More about extension
Thesaurus: All synonyms and antonyms for "extension" Medical Dictionary: Definition of "extension" Spanish Central: Translation of "extension" Nglish: Translation of "extension" for Spanish speakers Britannica English: Translation of "extension" for Arabic speakers Britannica.com: Encyclopedia article about "extension"
Seen and Heard
What made you want to look up extension? Please tell us where you read or heard it (including the quote, if possible).