Home › Words › S › siriometersiriometersiriometer means A unit of distance equal to one million astronomical units or 15.813 light-years.EtymologyFrom Sirius + -o- + meter. It is roughly twice the distance from Earth to the star Sirius.nounA unit of distance equal to one million astronomical units or 15.813 light-years.Definitions & examples from Wiktionary (CC BY-SA 3.0).