The Collaborative International Dictionary
Lightning \Light"ning\ (l[imac]t"n[i^]ng), n. [For lightening, fr. lighten to flash.]
A discharge of atmospheric electricity, accompanied by a vivid flash of light, commonly from one cloud to another, sometimes from a cloud to the earth. The sound produced by the electricity in passing rapidly through the atmosphere constitutes thunder.
-
The act of making bright, or the state of being made bright; enlightenment; brightening, as of the mental powers. [R.]
Ball lightning, a rare form of lightning sometimes seen as a globe of fire moving from the clouds to the earth.
Chain lightning, lightning in angular, zigzag, or forked flashes.
Heat lightning, more or less vivid and extensive flashes of electric light, without thunder, seen near the horizon, esp. at the close of a hot day.
Lightning arrester (Telegraphy), a device, at the place where a wire enters a building, for preventing injury by lightning to an operator or instrument. It consists of a short circuit to the ground interrupted by a thin nonconductor over which lightning jumps. Called also lightning discharger.
Lightning bug (Zo["o]l.), a luminous beetle. See Firefly.
Lightning conductor, a lightning rod.
Lightning glance, a quick, penetrating glance of a brilliant eye.
Lightning rod, a metallic rod set up on a building, or on the mast of a vessel, and connected with the earth or water below, for the purpose of protecting the building or vessel from lightning.
Sheet lightning, a diffused glow of electric light flashing out from the clouds, and illumining their outlines. The appearance is sometimes due to the reflection of light from distant flashes of lightning by the nearer clouds.
Wiktionary
n. More or less vivid and extensive flashes of electric light, without thunder, seen near the horizon, especially at the close of a hot day.
WordNet
n. bright flashes of light near the horizon without thunder (especially on hot evenings); usually attributed to distant lightning that is reflected by clouds
Wikipedia
Heat lightning, sometimes known as silent lightning, is the name used for the faint flashes of lightning on the horizon or other clouds from distant thunderstorms that do not have accompanying sounds of thunder. This often occurs because of inter-cloud and intra-cloud lightning, where lightning charges travel from cloud-to-cloud or merely areas of differing electric potential within a single cloud, respectively. Because of this nature, heat lightning can often be seen from great distances, and thus can be an early warning sign that thunderstorms are approaching. The term could be considered a misnomer because it has nothing to do with the heat of the lightning itself.
Heat lightning can also occur if cloud-to-ground lightning occurs very far away and the sound dissipates before it reaches the observer. At night, it is possible to see the flashes of lightning from very far distances, up to 100 miles, but the sound does not carry that far. In Florida, heat lightning is often seen over the water at night, the remnants of storms that formed during the day along a sea breeze front coming in from the opposite coast.
Heat lightning also occurs where airborne matter muffles the thunder, such as heavy snow in winter storms ( thundersnow) and dust and sand storms. In some instances, heavy falling snow has silenced thunder from cloud to ground lightning strikes as close as one to two miles (1.6 to 3.2 km) from the observer and severe dust storms are even more effective in many cases.
Heat lightning is not to be confused with electrically-induced luminosity actually generated at mesospheric altitudes above thunderstorm systems (and likewise visible at exceedingly great ranges), a phenomenon known as " sprites".
Heat Lightning is a 1934 Pre-Code drama film starring Aline MacMahon, Ann Dvorak, and Preston Foster. It is based on the play of the same name by Leon Abrams and George Abbott.
The movie was one of the last to be released before the Motion Picture Production Code was rigorously enforced. According to Robert Osborne of Turner Classic Movies, two months after its release, it was banned by the Catholic League of Decency.
Usage examples of "heat lightning".
Sighing, Aviendha gave up trying to ignore her companions' conversation behind her, though irritation crackled through it like heat lightning.
Aes Sedai were supposed to be cool serenity itself, and she was that, but Alanna tossed off flashes of fiery temper or unpredictable humor when least expected, like heat lightning, crackling then gone.
Flashes of heat lightning occurred in the west, and the winds grew stronger.
The whole of her body went up in an instant, like dry leaves sparked by heat lightning.
Words are the light and sound of our existence, the heat lightning by which the night is illuminated.
The sky was canary yellow and full of dust, and great fearsome sheets of dry heat lightning crackled all evening, and everything smelled of filth and sweat and ozone, and the people were actively savoring this situation.
A hundred miles away to the southwest he could see heat lightning flickering.