Vertical kampong means: A programme that aims to instill a sense of social cohesion in communities living in high-rise apartments through informal volunteerism.. It is mainly Singaporean 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.