Radar/ˈreɪdɑːr/ Definition 1 of 3Pro Tip 1/3Technical Equipment Refers to devices used for safety in vehicles and weather predicting. The ship's captain checked the radar for nearby vessels. Pro Tip 2/3Beyond Vision Helps detect objects too far or conditions too poor for the human eye. Air traffic controllers rely on radar to track planes in the night sky. Pro Tip 3/3Not Just Military Though associated with military, it's used in many civilian applications. Weather forecasters use radar to map out rain conditions.