Glow accompanying the brushlike discharges of atmospheric electricity that usually appears as a tip of light on the extremities of such pointed objects as church towers or the masts of ships during stormy weather.
It is commonly accompanied by a crackling or fizzing noise. It is commonly observed on the periphery of propellers and along the wing tips, windshield, and nose of aircraft flying in dry snow, in ice crystals, or near thunderstorms. St. Elmo is an Italian corruption of St. Erasmus, patron saint of Mediterranean sailors, who traditionally regarded St. Elmo's fire as a sign of his guardianship over them.