J4J Full Form. Full Meaning of J4J Find long form and abbreviation, slang or definition of J4J. What does J4J mean? What does J4J 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.