Offline activity?

I believe the answer is:

improv

(Other definitions for improv that I've seen before include "Off-the-cuff comedy" , "off-the-cuff humour" , "Stand-up comedy, perhaps" , "little ad-libbing" .)

I've seen this clue in The New York Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.