Improvisation is the act of creating or performing something without preparation or preconceived plans. Various synonyms are available to describe this term, including extemporize, spontaneous, impromptu, instinctive, and ad-lib. Improvise is often used in the context of music, where talented musicians can improvise for hours without any previous planning. The word "extemporize" is also commonly used in musical contexts and means to create or perform something without any prior planning. Impromptu means spontaneous and unplanned, while instinctive means that something is done naturally without any conscious decision. Ad-lib is a term used primarily in theater and film and means that the actor is improvising their lines without a script.