"adr fail" means: A round, game, or performance where a player's Average Damage per Round comes in embarrassingly low — the kind of output that reveals they s.... This is a fairly neutral word with no inherent risk attached. There is no real cause for parental concern; it is descriptive vocabulary rather than something dangerous. If your child uses it, context will usually make the meaning clear. A brief, curious question about where they heard it is generally enough to know whether to follow up.