The Collaborative International Dictionary
Zodiacal \Zo*di"a*cal\, a. [Cf. F. zodiacal.] (Astron.) Of or pertaining to the zodiac; situated within the zodiac; as, the zodiacal planets.
Zodiacal light, a luminous tract of the sky, of an elongated, triangular figure, lying near the ecliptic, its base being on the horizon, and its apex at varying altitudes. It is to be seen only in the evening, after twilight, and in the morning before dawn. It is supposed to be due to sunlight reflected from multitudes of meteoroids revolving about the sun nearly in the plane of the ecliptic.
Wiktionary
n. (context astronomy English) A soft glow of white light extending upward from the horizon along the ecliptic, particularly in the tropics.
WordNet
n. a luminous tract in the sky; a reflection of sunlight from cosmic dust in the plane of the ecliptic; visible just before sunrise and just after sunset
Wikipedia
Zodiacal light is a faint, roughly triangular, diffuse white glow seen in the night sky that appears to extend up from the vicinity of the Sun along the ecliptic or zodiac. It is caused by sunlight scattered by space dust in the zodiacal cloud. It is best seen just after sunset in spring, and just before sunrise in autumn, when the zodiac is at a steep angle to the horizon, but is so faint that either moonlight or light pollution renders it invisible.
The zodiacal light decreases in intensity with distance from the Sun, but on very dark nights it has been observed in a band completely around the ecliptic. In fact, the zodiacal light covers the entire sky and is responsible in large part for the total skylight on a moonless night. Another phenomenon—a faint, but slightly increased, oval glow directly opposite the Sun—is called the gegenschein.
The dust forms a thick pancake-shaped cloud in the Solar System collectively known as the zodiacal cloud, which occupies the same plane as the ecliptic. The dust particles are between 10 and 300 micrometres in diameter, most with mass around 150 micrograms.
Usage examples of "zodiacal light".
Soon her monitors showed that data was starting to come in on hydrogen alpha emission, ultraviolet line spectra, ultraviolet and X-ray imaging, spectrography of the active regions, zodiacal light, spectroheliographs.
And the flat belt of light farther out was the zodiacal light, the shining of dust particles and meteorites and asteroids in the plane of the ecliptic.
Dimmed by the optics to mere moon brightness, so that corona and zodiacal light shone at their natural luminosities like nacre, that disc still drove most of the distant suns out of a watcher's eye.
The zodiacal light stretched out from the Sun's middle clear across the width of the port.
The zodiacal light, in the Solar System, was a faint glow along the plane of the ecliptic.
About it, in far flung streamers of cold fire shone the mighty zodiacal light, an Aurora on a titanic scale.
Find the Zodiacal Light and maneuver into the dust blanket around the sun while still heading for the sun.
There was a powerful zodiacal light in the Luyten 726 system, and the stars shone in profusion.
Then, seeping faintly over the windows around the tower, the air-glow of the zodiacal light.
A kind of dawn was breaking in the northeast, zodiacal light strengthened by the nearness of the sun.
Its radiance stopped down in simulacrum, the sun burned amidst a glory of corona and zodiacal light.
It grew hotter, and the western blaze climbed into the sky until you could see the great lens of zodiacal light just above the hills, and more natives joined the procession until there were several thousand pouring along the road.