(informal) Improvisation. / (acting) A form of live entertainment characterized by improvisation and interaction with the audience.

To perform improv.

That tends to improve someone or something (especially (dated) to educate or morally better a person).

present participle of improve

Capable of being improved. / Capable of being used to advantage; profitable.

Impossible to prove.

simple past tense and past participle of improvize

The condition of being improvable

plural of improv

Third-person singular simple present indicative form of improv