extemporary

unrehearsed, improvised

Synonyms: ad hoc, ad lib, at first glance, automatic, by ear, casual, expedient, extempore, free, immediate, impromptu, improv, improvisatory, improviso, informal, jamming, made-up, makeshift, offhand, off the cuff, off the top of head, on impulse, on-the-spot, snap, spontaneous, spur-of-the-moment, taking for ride, thought out loud, tossed off, tossed out, unplanned, unpremeditated, unprepared, unstudied, winging it

Antonyms: planned, prepared, read, rehearsed, written