<p><strong>Adjective</strong></p><ul><li>Done, spoken, performed, etc., without special advance preparation; impromptu: an extemporaneous speech.</li><li>Previously planned but delivered with the help of few or no notes: extemporaneous lectures.</li><li>Speaking or performing with little or no advance preparation: extemporaneous actors.</li><li>Made for the occasion, as a shelter.</li></ul>