Adult maxxing means: Adult maxxing is the act of going all-in on being a functional, responsible adult - optimising every corner of your life for stability, competence, and general maturity. Think batch cooking,. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. This is a food-related word and harmless in itself. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.