Radar means: In full primary radar: a method of detecting a distant object and determining its position, velocity, or other characteristics by analysing radio waves (usually microwaves) which are sent towards the. It has drug-related associations; worth a calm conversation about which side of the topic your teen is on. 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.