Not rehearsed. See Synonyms at extemporaneous .

with little or no preparation or forethought; "his ad-lib comments showed poor judgment"; "an extemporaneous piano recital"; "an extemporary lecture"; "an extempore skit"; "an impromptu speech"; "offhand excuses"; "trying to sound offhanded and reassuring"; "an off-the-cuff toast"; "a few unrehearsed comments"[syn: ad-lib ]

adjective

ad-lib * , extemporaneous , from the hip , impromptu , improvised , impulsive , not rehearsed , off the cuff * , off the top of one’s head , spur of the moment , unpracticed , unprepared , ad-lib , extemporary , extempore , offhand , snap , spur-of-the-moment , informal , spontaneous