Fuselloviridae is a term used to describe a family of viruses that infect archaea, which are single-celled microorganisms. Synonyms for Fuselloviridae that may be used interchangeably include fusiform virus, spindle-shaped virus, and spindle virus. These viruses have a unique morphology due to their spindle or fusiform shape, which is derived from their structural proteins. These viruses have been found in various environments, including deep-sea hydrothermal vents and acidic hot springs. Fuselloviridae viruses are known to cause lysis of host cells and have been extensively studied for their unique relationships with archaea. Understanding the various synonyms for this term can help researchers communicate more effectively in the field of virology.