Abu mode means: A heightened state of tribal football fandom in which a person or group is actively rooting for anyone playing against Manchester United, regardless of personal club allegiance. Fully activated. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. It is sporting vocabulary 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.