zodiacal light

WordReference Random House Unabridged Dictionary of American English © 2026

zodi′acal light′, 

1. Astronomy a luminous tract in the sky, seen in the west after sunset or in the east before sunrise and thought to be the light reflected from a cloud of meteoric matter revolving round the sun.

• 1725–35

Collins Concise English Dictionary © HarperCollins Publishers::

zodiacal light noun

1. a very faint cone of light in the sky, visible in the east just before sunrise and in the west just after sunset. It is probably due to the reflection of sunlight from cosmic dust in the plane of the ecliptic