Radar used to mean "RAdio Detection And Ranging." R.A.D.A.R. Then it became something we all knew about. Then the cops got it. Then it became a word. Today, you might not have to capitalize and punctuate "radar" the way you once had to. But that doesn't mean you should fear it any less. The military uses it to track the enemy. The cops can use it to track you. AHEM.