- the art or act of improvising, or of composing, uttering, executing, or arranging anything without previous preparation: Musical improvisation involves imagination and creativity.
- something improvised: The actor’s improvisation in Act II was both unexpected and amazing.
- the act or an instance of improvising
- a product of improvising; something improvised
mid-15c., “unforeseen happening;” 1786 as “act of improvising musically,” from French improvisation, from improviser “compose or say extemporaneously,” from Italian improvvisare, from improvviso “unforeseen, unprepared,” from Latin improvisus “not foreseen, unforeseen, unexpected,” from assimilated form of in- “not, opposite of” (see in- (1)) + provisus “foreseen,” also “provided,” past participle of providere “foresee, provide” (see provide).