(obsolete) the lack of provision, a failure to provide something

the act of improvising, or something improvised; improvisation

plural of improvision

plural of improvised explosive device

An unconventional or amateur explosive weapon made from nonmilitary components, especially one used by guerillas, commandos or terrorists.

plural of improvisational comedy

a form of theatre in which the actors perform spontaneously, without a script

A form of improvisational theatre performed with little predetermination of subject matter and structure, but with interaction with the audience. / An instance of such theatre.