1. A condition in which there is only gloom, poor, or inconsistent light.: A figure emerged from the murk as Jane and James walked down the street in the evening.
2. Gloomy darkness caused by fog, mist, smoke, or cloud: In the harbor, the industrial murk was further exacerbated by the heavy fog causing the special horns to sound throughout the night.
3. Darkness or a thick cloud, which prevents people from seeing clearly: Aurora and Walter carried their flashlights when they walked through the murk on their way home.
4. Dark or dirty water: When Stephan was rowing a boat, he couldn't see the bottom of the lake through all the murk that was there.
5. Etymology: from Middle English mirke, from Old Norse myrkr, or Old English mirce, "dark".