Extension

//ɪkˈstɛnʃən// noun

noun ·Very common ·Middle school level

Definitions

Noun
  1. 1
    The act of extending; a stretching out; enlargement in length, breadth, or time; an increase. countable, uncountable

    "Next month the house is undergoing an extension."

  2. 2
    act of expanding in scope; making more widely available wordnet
  3. 3
    The state of being extended. countable, uncountable

    "For station is properly no rest, but one kind of motion, relating unto that which physicians (from Galen) do name extensive or tonical; that is, an extension of the muscles and organs of motion, maintaining the body at length, or in its proper figure."

  4. 4
    act of stretching or straightening out a flexed limb wordnet
  5. 5
    That property of a body by which it occupies a portion of space (or time, e.g. "spatiotemporal extension"). countable, uncountable
Show 28 more definitions
  1. 6
    an educational opportunity provided by colleges and universities to people who are not enrolled as regular students wordnet
  2. 7
    A short exact sequence 1→H→E→G→1, or the group E therein. countable, uncountable
  3. 8
    an addition that extends a main building wordnet
  4. 9
    A short exact sequence 0→B→E→A→0, or the object E therein. countable, uncountable
  5. 10
    an addition to the length of something wordnet
  6. 11
    A part of a building that has been added onto the original. countable, uncountable
  7. 12
    an additional telephone set that is connected to the same telephone line wordnet
  8. 13
    An outgrowth; a part of something that extends its capabilities. countable, uncountable

    "Parents who treat their children as an extension of themselves"

  9. 14
    amount or degree or range to which something extends wordnet
  10. 15
    Capacity of a concept or general term to include a greater or smaller number of objects; — correlative of intension. countable, uncountable

    "Perversely, we love John Wick himself. That lethal, bereaved assassin is a good bad guy for our times, the natural extension of Tony Soprano, Walter White and all the other heroic antiheroes the culture has embraced."

  11. 16
    the ability to raise the working leg high in the air wordnet
  12. 17
    semantic widening, broadening of meaning countable, uncountable
  13. 18
    the most direct or specific meaning of a word or expression; the class of objects that an expression refers to wordnet
  14. 19
    A written engagement on the part of a creditor, allowing a debtor further time to pay a debt. countable, uncountable
  15. 20
    the spreading of something (a belief or practice) into new regions wordnet
  16. 21
    The operation of stretching a broken bone so as to bring the fragments into the same straight line. countable, uncountable
  17. 22
    a string of characters beginning with a period and followed by one or more letters; the optional second part of a PC computer filename wordnet
  18. 23
    An exercise in which an arm or leg is straightened against resistance. countable, uncountable
  19. 24
    a mutually agreed delay in the date set for the completion of a job or payment of a debt wordnet
  20. 25
    A simple offensive action, consisting of extending the weapon arm forward. countable, uncountable
  21. 26
    A numerical code used to indicate a specific telephone in a telecommunication network. countable, uncountable
  22. 27
    Ellipsis of file extension. abbreviation, alt-of, countable, ellipsis, uncountable

    "Files with the .txt extension usually contain text."

  23. 28
    An optional software component that adds functionality to an application. countable, uncountable

    "a browser extension"

  24. 29
    The set of tuples of values that, used as arguments, satisfy the predicate. countable, uncountable
  25. 30
    A kind of derivative morpheme applied to verbs in Bantu languages. countable, uncountable
  26. 31
    The ideal in the codomain generated by the image of the given ideal under the given homomorphism. countable, uncountable
  27. 32
    University programs that are targeted at the broader (usually adults) community whose participants are not full-time enrolled students. countable, uncountable
  28. 33
    Clipping of hair extension, nail extension, or eyelash extension. abbreviation, alt-of, clipping, countable, in-plural, uncountable

Synonyms

All synonyms
annexdenotationdenotationelongationreferenceaccess

Example

More examples

"The extension of summer vacation delighted the children."

Etymology

From Middle English extensioun, from Old French estension, from Latin extensiō, extensiōnem.

Related phrases

Buck's extensionExtension ScoutGalois extensionKan extensionagricultural extensionalgebraic extensionback extensionby extensionconservative extensionconvergent extensioncurb extensiondemarc extension

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.