extemporise

/ɪkˈstɛmpəraɪz/
verb
  1. To speak or perform without preparation or rehearsal; to improvise.
    • Jazz musicians often extemporise solos based on the chord changes.
    • She had to extemporise when the microphone stopped working.
    • The teacher asked him to extemporise a short speech on friendship.
Antonyms
What does "extemporise" mean? | whatsthatwordmean | whatsthatwordmean