Baasskap means: Dominion, control, or supremacy, especially of white South Africans over nonwhite peoples.. It is mainly South African English and may not be understood outside that context. 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.