Answer: extemporaneous

AnswerCrossword Clue
EXTEMPORANEOUSImpromptu
EXTEMPORANEOUSKind of speech
EXTEMPORANEOUSUnprepared
extemporaneousSpoken or done without preparation
extemporaneousunpremeditated; esp of prayer, discourse, composition, etc also EXTEMPORARY, EXTEMPORE