Sidekick Cycle is a popular term these days and is often used to describe a two-seater bicycle. However, many synonyms can be used instead of this term. For instance, tandem bike, which is used to describe a bicycle built for two. Furthermore, "bicycle for two" is another phrase that can be used in place of sidekick cycle. Additionally, "dual bikes," "double bikes" and "twin bicycles" are also great synonyms for a two-seater bicycle. Some people may even refer to a sidekick cycle as a "duo bike," implying two people riding together on the same bike. In summary, there are many ways to describe a two-seater bicycle, and Sidekick Cycle is just one of them.