Literally, "twilight rays", alternating lighter and darker bands (rays and shadows) which appear to diverge in fan-like array from the sunâ€™s position at about twilight. The apparent divergence of crepuscular rays is, of course, merely a perspective effect.
Alternating light and dark bands of light that appear to fan out from the sun's position, usually at twilight.
Contrasting, alternating bright and dark rays in the sky. Sunlight is scattered by molecules and particles rendering these bright rays visible. Contrast is enhanced by haze, dust, or mist. These rays are more likely to be seen in the late afternoon, as clouds come between the sun and the observer. A similar effect occurs when the sun shines though a break in a layer of clouds.