impromptu Synonyms

ad libitum offhand extempore extemporary extemporaneous unrehearsed offhanded off-the-cuff ad lib spontaneously stopgap on impulse offhandedly off-hand improv extemporaneously unpremeditated unprepared by ear improvisational on the fly on the spot unplanned according to pleasure as one thinks best off the top of head as one wishes without rehearsal without preparation unscripted unsolicited unprompted unposed uncontrived unarranged unannounced spur of the moment rough and ready precipitously ad hoc throwaway pickup improvisatory improvisatorial improvisation horseback headfirst glancingly freewill extemporized