Meaning of “improvise” - Learner’s Dictionary

improvise

verb [ I, T ] us uk /ˈɪmprəvaɪz/
MAKE

to make or do something without any preparation, using only the things that are available:

For a football, we improvised with some rolled-up socks.
PERFORM

to play music or say words that you are inventing, not reading or remembering:

The show is not scripted - the actors have to improvise.
improvisation noun [ C, U ] us uk /ˌɪmprəvaɪˈzeɪʃən/

(Definition of “improvise” from the Cambridge Learner’s Dictionary © Cambridge University Press)