"brainrot fail" means: A brainrot fail is when content tries to be chaotic, unhinged, and algorithmically corrupted but falls flat — the meme is off, the reference.... 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.