Synonyms for Improv:

• adj.

  •extemporaneous/extemporary (adjective)
  • unpremeditated,
  • expedient,
  • winging it,
  • made-up,
  • makeshift,
  • snap,
  • ad hoc,
  • spontaneous,
  • extempore,
  • automatic,
  • unstudied,
  • unprepared,
  • offhand,
  • free,
  • casual,
  • immediate,
  • spur-of-the-moment,
  • unplanned.
  •impromptu (adjective)
  • Extemporized,
  • played by ear,
  • winged,
  • Vamped,
  • whipped up,
  • fake,
  • faked,
  • ad-lib.
  •informal (adjective)
  • easy,
  • unofficial,
  • congenial,
  • open,
  • mellow,
  • unceremonious,
  • intimate,
  • ordinary,
  • democratic,
  • everyday,
  • loose,
  • inconspicuous,
  • frank,
  • Familiar,
  • cool,
  • natural,
  • urbane,
  • unrestrained,
  • straightforward,
  • mixed,
  • unconstrained,
  • breezy,
  • homey,
  • unconventional,
  • sporty,
  • colloquial,
  • relaxed,
  • easygoing.
  •off the cuff (adjective)
  • improvised,
  • off-hand,
  • unrehearsed.

• a. & adv.

  •impromptu (adjective, adverb)
  • un scripted.

• adv.

  •off the cuff (adverb)
  • off the hip,
  • extemporaneously,
  • spur of the moment,
  • off the top of one's head.

• v.

  •improvise (verb)
  • invent,
  • jam,
  • devise,
  • contrive,
  • brainstorm,
  • extemporize,
  • knock off,
  • dream up,
  • concoct,
  • coin,
  • slapdash,
  • spark.
  •make up (verb)
  • improvise,
  • formulate,
  • mix,
  • write,
  • Fabulize,
  • originate,
  • frame,
  • play by ear,
  • fabricate,
  • meld,
  • hatch,
  • fix,
  • construct,
  • compose,
  • join,
  • fuse,
  • cook up,
  • Storify,
  • merge,
  • mingle,
  • ready,
  • compound,
  • make,
  • pretend,
  • put together,
  • blend,
  • whip up,
  • prepare,
  • combine,
  • fictionalize,
  • fashion,
  • trump up.
  •wing it (verb)
  • play it by ear.

• Other synonyms:

  •create
  • make up.
  •make up
  • writes,
  • makes up,
  • storified,
  • made up.

Antonyms for Improv:

• adj.

  • extemporaneous
    premeditated.
  • extemporaneous/extemporary
    written, prepared, Rehearsed, read, planned.
  • impromptu
    deliberate.
  • informal
    rigid, official, formal, ceremonious, stiff, dressed-up, buttoned-up.

• n.

  • Other antonyms:
    bit, drill, routine.

• v.

  • improvise
    devise, design, premeditate, plan.
  • make up
    disagree, be real, tell truth.