[1] : The Collaborative International Dictionary of English v.0.48

improvise \im`provise"\, v. t. imp.  p. p. improvised; p.
   pr.  vb. n. improvising. f. improviser, it.
   improvvisare, fr. improvviso unprovided, sudden, extempore,
   l. improvisus; pref. im- not + provisus foreseen, provided.
   see proviso.
   1. to compose, recite, or sing extemporaneously, especially
      in verse; to extemporize; also, to play upon an
      instrument, or to act, extemporaneously.
      1913 webster

   2. to bring about, arrange, do, or make, immediately or on
      short notice, without previous preparation and with no
      known precedent as a guide.
      1913 webster +pjc

            charles attempted to improvise a peace. --motley.
      1913 webster

   3. to invent, or provide, offhand, or on the spur of the
      moment; as, he improvised a hammer out of a stone.
      1913 webster
see also:
improvised improvising proviso 

[2] : WordNet (r) 2.0

improvised
     adj : done or made using whatever is available; "crossed the river
           on improvised bridges"; "the survivors used jury-rigged
           fishing gear"; "the rock served as a makeshift hammer"
           syn: jury-rigged, makeshift
see also:
jury-rigged makeshift 

[3] : Moby Thesaurus II by Grady Ward, 1.0

52 moby thesaurus words for "improvised":
   ad hoc, ad libitum, ad-lib, band-aid, caught napping,
   caught off balance, caught short, extemporaneous, extemporary,
   extempore, extemporized, haphazard, hasty, impromptu,
   improvisational, improvisatorial, improvise, improviso,
   jury-rigged, makeshift, makeshifty, off-the-cuff, offhand,
   precipitate, provisional, rough-and-ready, snap, stopgap,
   surprised, taken aback, taken by surprise, taken unawares,
   temporary, tentative, tripped up, unarranged, unbegun, unconcocted,
   uncontrived, undeliberated, undevised, unhatched, unmade,
   unmanufactured, unorganized, unplanned, unpremeditated, unprepared,
   unprimed, unready, unrehearsed, unstudied

Improvised >> I Words
Improvised, definition of term: Improvised
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