(imp. & p. p.) of Improvise.

ad hoc ad libitum ad-lib band-aid caught napping caught off balance caught short extemporaneous extemporary extempore extemporized haphazard hasty impromptu improvisational improvisatorial improvise improviso jury-rigged makeshift makeshifty off-the-cuff offhand precipitate provisional rough-and-ready snap stopgap surprised taken aback taken by surprise taken unawares temporary tentative tripped up unarranged unbegun unconcocted uncontrived undeliberated undevised unhatched unmade unmanufactured unorganized unplanned unpremeditated unprepared unprimed unready unrehearsed unstudied