extemporaneous: Meaning and Definition of

ex•tem•po•ra•ne•ous

1. done, spoken, performed, etc., without special advance preparation; impromptu: an extemporaneous speech.
2. previously planned but delivered with the help of few or no notes: extemporaneous lectures.
3. speaking or performing with little or no advance preparation: extemporaneous actors.
4. made for the occasion, as a shelter.