St. Elmo's fire
- An intermittent, luminous, and often audible electrical discharge that originates from a conductor when its potential exceeds a given value, but is not high enough to form a spark. This occurs especially in pointed objects when the electric field near their surfaces surpasses a given amount. For example, an aircraft traveling through an electrical storm may develop such discharges from an antenna, which in turn produces precipitation static. Also called corona discharge, corona effect, corona, brush discharge, or corposant.