Snarl-up means: British, Australian, and New Zealand slang for a traffic jam - a tangle of vehicles that has brought movement to a halt. By extension it can mean any kind of organizational or procedural mess that. It is mainly New Zealand English and may not be understood outside that context. It has drug-related associations; worth a calm conversation about which side of the topic your teen is on. As a place or proper-name reference it is purely descriptive.