extemporising

Verb

extemporise (third-person singular simple present extemporises, present participle extemporising, simple past and past participle extemporised)

1. (intransitive) To do something, particularly to perform or speak, without prior planning or thought; to act in an impromptu manner; to improvise.
2. (intransitive) To do something in a makeshift way.
3. (transitive) To make or create ex tempore.
4. (transitive) To compose extemporaneously or improvise.