Yampy mode means: The specific mental state when someone has checked out of sensible thinking and fully committed to operating on pure daftness. Yampy mode isn't permanent madness - it's a temporary activation,. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. 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.