34 definitions of OSS. Definition of OSS in Military and Government. What does OSS stand for?. Looking for the definition of OSS? Find out what is the full meaning of OSS on izbori2007.eu! 'Open Source Software' is one option -- get in to view more. definitions of OSS. Meaning of OSS. What does OSS stand for? OSS abbreviation. Define OSS at izbori2007.eu. Retrieved July 6 from http: All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes. Other terms relating to 'software': Not what you were looking for? Out of School Suspension.