A shortage of pentobarbital has forced some states to improvise, often with gruesome consequences.
OK guys, now rip it out and improvise and say anything you want.
Thus, there was no time for the usual frat pack scenes in which the director says, “improvise here.”
1826, back-formation from improvisation, or else from French improviser (17c.), from Italian improvisare "to sing or speak extempore," from improviso, from Latin improvisus "unforeseen, unexpected" (see improvisation). Or possibly a back-formation from improvisation. Related: Improvised; improvising.