25B6; verb she ad-libbed half the speech : IMPROVISE, extemporize, speak impromptu, play it by ear, make it up as one goes along; informal busk it, wing it.
25B6; adverb she spoke ad lib : IMPROMPTU, extempore, without preparation, without rehearsal, extemporaneously; informal off the cuff, off the top of one's head.
25B6; adjective a live, ad-lib commentary : IMPROMPTU, extempore, extemporaneous, extemporary, improvised, unprepared, unrehearsed, unscripted; informal off-the-cuff, spur-of-the-moment.