Murky means dark, cloudy, and difficult to see through. A murky pond is so full of mud and algae that you can't see the bottom, even in shallow water. Murky water makes you hesitate before wading in because you don't know what you might step on.

A murky sky is heavy with dark clouds. A murky alley at night feels unsafe because the shadows hide what's there.

Beyond describing physical darkness, murky describes situations where the truth is hard to find. When a mystery has murky details, the facts are confused or deliberately hidden. Scientists studying a murky question face evidence that points in different directions. If someone gives you a murky explanation of why they were late, their story is vague and suspicious, leaving you uncertain whether they're telling the truth.

The word suggests more than simple unclarity. Murky implies something questionable or troubling beneath the surface, whether that's mud in water or dishonesty in a story.