American Heritage Dictionary
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Century Dictionary
GNU Webster's 1913
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The ArtsCenter-It may seem contradictory, but one of the defining features of longform improv is the use of so-called "forms": By definition, nothing is scripted beforehand, but the performers usually work within a predetermined structure (rather like jazz, with its head, improvisation with solos, and return to the head).— Independent Weekly: All Recent Stories
HIGH SCHOOL IMPROV COMEDY CAMP Learn the fine art of improv, and show off your skills at an end-of-the-week performance of a completely improvised play.
Except if someone gets physically hurt on a ride or an improv, then you can stop.— Backseat Sandbar

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