To get mud on (something).

“If you muddy your shoes don't wear them inside.”

To make a mess of, or create confusion with regard to; to muddle.

“The discussion only muddied their understanding of the subject.”

Covered with or full of mud or wet soil.

“He slogged across the muddy field.”

With mud or other sediment brought into suspension, turbid.

“The previously limpid water was now muddy as a result of the epic struggle.”

Not clear; mixed up or blurry.