The Collaborative International Dictionary of English v.0.48:

Vacancy \Va"can*cy\, n.; pl. Vacancies. [Cf. F. vacance.]
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   1. The quality or state of being vacant; emptiness; hence,
      freedom from employment; intermission; leisure; idleness;
      listlessness.
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            All dispositions to idleness or vacancy, even before
            they are habits, are dangerous.       --Sir H.
                                                  Wotton.
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   2. That which is vacant. Specifically:
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      (a) Empty space; vacuity; vacuum.
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                How is't with you,
                That you do bend your eye on vacancy? --Shak.
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      (b) An open or unoccupied space between bodies or things;
          an interruption of continuity; chasm; gap; as, a
          vacancy between buildings; a vacancy between sentences
          or thoughts.
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      (c) Unemployed time; interval of leisure; time of
          intermission; vacation.
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                Time lost partly in too oft idle vacancies given
                both to schools and universities. --Milton.
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                No interim, not a minute's vacancy. --Shak.
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                Those little vacancies from toil are sweet.
                                                  --Dryden.
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      (d) A place or post unfilled; an unoccupied office; as, a
          vacancy in the senate, in a school, etc.
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WordNet (r) 3.0 (2006):

vacancy
    n 1: being unoccupied
    2: an empty area or space; "the huge desert voids"; "the
       emptiness of outer space"; "without their support he'll be
       ruling in a vacuum" [syn: void, vacancy, emptiness,
       vacuum]