- warren (n.)
- late 14c., "piece of land enclosed for breeding beasts and fowls," from Anglo-French and Old North French warenne, Old French garenna "game park," possibly from Gaulish *varenna "enclosed area," related to *varros "post." Or the Old French forms may derive from the present participle of Old French warir "defend, keep," from the Germanic root *war- "to protect, guard" (source of Old English warian "take care;" see warrant (n.)). Later especially "piece of land for breeding of rabbits" (c.1400), which led to the transferred sense of "cluster of densely populated living spaces" (1640s).