improvisation
noun /ˌɪmprəvaɪˈzeɪʃn/
/ɪmˌprɑːvəˈzeɪʃn/
[uncountable, countable]- the act of inventing music, the words in a play, a statement, etc. while you are playing or speaking, instead of planning it in advance; something that is invented in this way
- jazz improvisation