Idle wheel is a term often used in mechanical engineering and refers to a type of gear that spins freely without engaging with other gears. There are several other synonyms for idle wheel that are commonly used in the industry, including idler gear, tensioner, and follower. These terms can be used interchangeably with idle wheel depending on the specific context and application. In some cases, the term idle pulley may also be used, which refers to a similar mechanism used in belt-driven systems. Despite the different names, these components all serve a similar purpose of maintaining tension and ensuring smooth rotation in mechanical systems.