Source : Webster's Revised Unabridged Dictionary (1913)

Warren \War"ren\, n. [Of. waresne, warenne, garene, F. garenne,
   from OF. warer, garer, to beware, to take care; of Teutonic
   origin; cf. OHG. war?n (in comp.), OS. war?n to take care, to
   observe, akin to E. wary. ????. See {Wary}.]
   1. (Eng Law)
      (a) A place privileged, by prescription or grant the king,
          for keeping certain animals (as hares, conies,
          partridges, pheasants, etc.) called beasts and fowls
          of warren. --Burrill.
      (b) A privilege which one has in his lands, by royal grant
          or prescription, of hunting and taking wild beasts and
          birds of warren, to the exclusion of any other person
          not entering by his permission. --Spelman.

                They wend both warren and in waste. --Piers
                                                  Plowman.

   Note: The warren is the next franchise in degree to the park;
         and a forest, which is the highest in dignity,
         comprehends a chase, a park, and a free warren.

   2. A piece of ground for the breeding of rabbits.

   3. A place for keeping flash, in a river.

Source : WordNet®

Warren
     n 1: United States writer and poet (1905-1989) [syn: {Robert Penn
          Warren}]
     2: United States jurist who served as chief justice of the
        United States Supreme Court (1891-1974) [syn: {Earl Warren}]
     3: a series of connected underground tunnels occupied by
        rabbits [syn: {rabbit warren}]
     4: an overcrowded residential area [syn: {rabbit warren}]
     5: a colony of rabbits