Obvious Jew
An OJ is a Jew so obvious, they might as well be wearing a star of David on their forehead. They usually have names that scream 'Jew' like a kid screaming in a math class. Don’t go around labeling every Daniel or Leah unless you're 100% sure they're actually Jewish.
'Daniel? That's an OJ. He's got the name to prove it.'
'Rachel? That's a real OJ. You can't miss it.'
'Ezra? That's an OJ. He's got the name, and that's that.'