A minor show or exhibition alongside of or near a principal one; hence, an incidental diversion or attraction; a by-play.(noun)
The Century Dictionary (Public Domain)
Use "side-show" in a sentence
"Nothing required but a willing Actor without any real threat to invoke Terror, and with the additional side-show (think the Flying Imams also), to put off and divert attention to the Political as they prepare/plan their next attacks on the US."
"There isn't one laptop in the show, however; every film, video, DVD, or what-show-you is seen in a dedicated viewing context, whether cast upon a large screen, seen on a small screen in a booth, or even peeked at through an updated version of a side-show mutoscope."
"So now that the Repugicans have had their side-show grandstanding for the Party "base", we can get on with the business of government."