Definition: Improvisation is a type of comedy (or acting) where there is no script; it is free-form and requires the performers to make up dialogue and situations as they go along. There are many theaters and comedy troupes that specialize in improvisation. Some, like Second City, use improvisation as a way of creating concrete material for full-length shows. Others, like the Improv Olympic or the Upright Citizens Brigade Theater, offer improvisation as the show itself.
Also Known As: Improv; ad-lib
Examples:The audience called out for an improvisation set inside a classroom, so the actors made up a scene between a clueless teacher and her class as we all watched.