Source : Webster's Revised Unabridged Dictionary (1913)

Warden \Ward"en\, n. [OE. wardein, OF. wardein, gardein,
   gardain, F. gardien. See {Guardian}, and {Ward} guard.]
   1. A keeper; a guardian; a watchman.

            He called to the warden on the . . . battlements.
                                                  --Sir. W.
                                                  Scott.

   2. An officer who keeps or guards; a keeper; as, the warden
      of a prison.

Source : WordNet®

warden
     n : the chief official in charge of a prison [syn: {warder}]