1911 Encyclopædia Britannica/Warren

WARREN, properly an old term of the English forest law, derived from the O. Fr. warenne, varenne, garenne (med. Lat. warenna, warir, to guard, cf. “ward”), and applied to one of the three lesser franchises, together with “chase” and “park,” included under the highest franchise, the “forest,” and ranking last in order of importance. The “beasts of warren” were the hare, the coney (i.e. rabbit), the pheasant and the partridge. 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 (see Forest Laws).