I am in doubt about a phrasal verb I have bumped into when reading an article in English and no dictionary in my research seem to be clear or understandable in its explanation....

...and here it is " Spin off "

And in context, it is....

Last night on TV there was this show about that actor who tries to get his big break in show biz. People thought it was a rerun but actually it was a pilot for a sitcom. Itīs a spin-off of a series that was really popular some time ago. Itīs a spoof of Hollywood and its stars but I thought it was way too slapstick for me. Even that famous actress, whatīs her name again, had a walk-on. She had a one-liner but her acting was a show-stopper.

"Itīs a spin-off of a series that was really popular some time ago".