expand

Recorded in Middle English since 1422 (as expanden, expaunden), from Anglo-Norman espaundre, from Latin expandere present active infinitive of expandō (“to spread out”), itself from ex- (“out, outwards”) + pandō (“to spread”). Doublet of spawn.

• Rhymes: -ænd
• IPA^(key): /ɪkˈspænd/, /ɛkˈspænd/

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expand (third-person singular simple present expands, present participle expanding, simple past and past participle expanded)

1. (transitive) To change (something) from a smaller form or size to a larger one; to spread out or lay open.

   You can expand this compact umbrella to cover a large table.

2. (transitive) To increase the extent, number, volume or scope of (something).

   A flower expands its leaves.

   • 1667, John Milton, “Book I”, in Paradise Lost. , London: [Samuel Simmons], and are to be sold by Peter Parker ; nd by Robert Boulter ; nd Matthias Walker, , →OCLC; republished as Paradise Lost in Ten Books: , London: Basil Montagu Pickering , 1873, →OCLC:

     Then with expanded wings he steers his flight.

   • 1961 October, “The winter timetables of British Railways: Scottish Region”, in Trains Illustrated, page 594:

     This has evidently been encouraging, for the current winter timetable - not even with the benefit of summer holiday traffic - shows that the two trains each way have been expanded to four.

3. (transitive) To express (something) at length and/or in detail.
4. (transitive, algebra) To rewrite (an expression) as a longer, yet equivalent sum of terms.

   Use the binomial theorem to expand ${\displaystyle {(x+1)}^{4}}$.

5. (intransitive, algebra, of an expression) To become, by rewriting, a longer, yet equivalent sum of terms.

   The expression ${\displaystyle {(x+1)}^{4}}$ expands to ${\displaystyle x^{4}+4x^{3}+6x^{2}+4x+1}$.

6. (transitive, arithmetic) To multiply both the numerator and the denominator of a fraction by the same (non-zero) number (which yields a fraction of equal value).

   Expanding ${\displaystyle 4/7}$ by ${\displaystyle 3}$ gives ${\displaystyle 12/21}$.

7. (intransitive) To change or grow from smaller to larger in form, number, or size.

   Many materials expand when heated.

   This compact umbrella expands to cover a large table.

8. (intransitive) To increase in extent, number, volume or scope.
9. (intransitive) To speak or write at length or in detail.

   He expanded on his plans for the business.

   • 1899, Stephen Crane, chapter 1, in Twelve O'Clock:

     There was some laughter, and Roddle was left free to expand his ideas on the periodic visits of cowboys to the town. “Mason Rickets, he had ten big punkins a-sittin' in front of his store, an' them fellers from the Upside-down-F ranch shot 'em up […] ”

10. (intransitive) To feel generous or optimistic.
11. (transitive, computing) In a hierarchical list (such as a directory tree or table of contents), to show the subentries of (an entry).

    Antonym: collapse

• (to change from a smaller form/size to a larger one): open out, spread, spread out, unfold
• (to increase the extent, number, volume or scope of): enlarge
• (to express at length or in detail): elaborate (on), expand on

• (antonym(s) of “to change from a smaller form/size to a larger one”): contract
• (antonym(s) of “to increase the extent, number, volume or scope of”): contract, limit
• (to express at length or in detail): limit
• (antonym(s) of “algebra: to rewrite as an equivalent sum of terms”): factor