skyglow 
noun [mass noun]
Brightness of the night sky in a built-up area as a result of light pollution: at night the stars and planets are obliterated by glare and skyglow...
- Light pollution occurs when too much artificial illumination enters the night sky and reflects off airborne water droplets and dust particles causing ‘skyglow’.
- A combination of skyglow, clouds, and insufficient aperture kept me from spotting it, though the sites farther east were much darker.
- It's the skyglow, from artificial lights and smog.
- foundation course
- foundation garment
- foundation stone
- foundation subjects
- founder
- founder effect
- founder member
- founder's day
- founding father
- founding member
- foundling
- found object
- foundress
- foundry
- fount
- fountain
- fountained
- fountainhead
- fountain pen
- Fountain Valley
- four
- four-bagger
- four-ball
- four-by-four
- Four Cantons, Lake of the