A sideshow is read as the strange, marginal attraction next to the main event. It may point to a distraction pulling your attention, or to a part of yourself that feels put on display as an oddity.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.