Having a wall of mud, or of materials laid in mud instead of mortar.
The Century Dictionary (Public Domain)
Use "mud-walled" in a sentence
"Students settled around him in the barren highlands of the Eastern Tibetan where the monks and nuns lived in simple mud-walled houses, burning yak dung for fuel."
"Villagers live in mud-walled homes that cling to the hillsides."
"More How the Death Notification Caused More Pain on the Home Front Snipers were out in force for the operation near Lwar Julji village, having been assigned the task of picking off enemy fighters while infantrymen swept through mud-walled compounds and farm fields."