Flopperoo means: A playfully emphatic word for a complete and total failure - the '-eroo' suffix kicks the disappointment up a notch, making the flop sound almost comically spectacular. Think a movie that bombs. 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.