Source : Webster's Revised Unabridged Dictionary (1913)

Sleeper \Sleep"er\, n.
   1. One who sleeps; a slumberer; hence, a drone, or lazy
      person.

   2. That which lies dormant, as a law. [Obs.] --Bacon.

   3. A sleeping car. [Colloq. U.S.]

   4. (Zo["o]l.) An animal that hibernates, as the bear.

   5. (Zo["o]l.)
      (a) A large fresh-water gobioid fish ({Eleotris
          dormatrix}).
      (b) A nurse shark. See under {Nurse}.