extemporizing

Verb

extemporize (third-person singular simple present extemporizes, present participle extemporizing, simple past and past participle extemporized)

1. (intransitive) To perform or speak without prior planning or thought; to act in an impromptu manner; to improvise.
   • "Will you please tell me whose music you have been playing?" . . .
     "It's nobody's, miss."
     "Do you mean you have been extemporizing all this time?"1881, George MacDonald, chapter 35, in Mary Marston
2. (transitive) To adapt, improvise, or devise action or speech in an impromptu or spontaneous manner.
   • As the music came fresher on their ears, they danced to its cadence, extemporizing new steps and attitudes.1860, Nathaniel Hawthorne, chapter 10, in The Marble Faun