"kennetjie" means: A children’s (boy’s) game where a short stick is flipped into the air by a longer stick, batted and hopefully caught by ‘fielders’.. 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.