A warren is a network of wild rabbit burrows. Domestic warrens are artificial, enclosed establishment of animal husbandry dedicated to the raising of rabbits for meat and fur. The term evolved from the medieval Anglo-Norman concept of free warren, which had been, essentially, the equivalent of a hunting license for a given woodland.
The use is further extended to any system of burrows, e.g., "prairie dog warren". By 164
The word thus became used of a piece of ground preserved for these beasts of warren. It is now applied loosely to any piece of ground, whether preserved or not, where rabbits breed.The use is further extended to any system of burrows, e.g., "prairie dog warren". By 1649, the term was applied to inferior, crowded human accommodations and meant "cluster of densely populated living spaces" (OED). Contemporarily, the leading use seems to be in the stock phrase "warren of cubicles" in the workplace.