ONS Full Form. Full Meaning of ONS Find long form and abbreviation, slang or definition of ONS. What does ONS mean? What does ONS stand for? We are providing world largest and most comprehensive acronyms, names, abbreviations database directory on the Internet. Our data base contains more than 8,00,000 terms abbreviations and acronyms. You can also search unique terms more than 4,00,000 general Comprehensive words.