Plain English Meaning
How much of the sky has clouds in it.
Full Definition
The degree to which the sky is covered by clouds at a given time and location, used in meteorology as a general descriptor of sky condition.
Context Anchor
You will see this idea in weather descriptions, preflight planning, and discussions of visibility and cloud conditions along a route.
Why Pilots Care
Affects whether visual flight rules are possible and signals potential hazards such as reduced visibility or turbulence.
Intuition Check
Cloudiness does not just mean the sky looks gray. In aviation, it means the cloud that may affect visibility, route choice, and whether the can be made safely under the rules you are using.