noun
murk
MURK/mɜːrk/
Darkness or thick haze that makes things hard to see.
The woodland path disappears into murk beyond the nearest trees.

Etymology
Old Norse myrkr named darkness itself. English murk preserves that concrete meaning, describing gloom that obscures what can be seen.
In context
She felt as though centuries of time had rolled over her head when the murk of the lowering sky lightened, and the London dawn was born, naked and grey.
More examples
- The diver disappears into the murk below the dock.
- We can just make out a doorway in the murk.
- Smoke fills the alley, and shapes vanish in the murk.
Forms
murky adjective — Dark or cloudy enough to obscure visibility.