Lightning/ˈlaɪtnɪŋ/ Definition 1 of 3Pro Tip 1/3Storm Indicator Lightning often signifies that a thunderstorm is nearby. The picnic was cut short when we spotted lightning. Pro Tip 2/3Safety Precaution During a lightning storm, seek shelter immediately to avoid danger. The hikers found a cave for cover from the lightning. Pro Tip 3/3Photography Challenge Capturing lightning in a photo requires patience and fast shutter speeds. He finally photographed the lightning after hours of waiting.