The Collaborative International Dictionary of English v.0.48:

Sleeping \Sleep"ing\,
   a. & n. from Sleep.
   [1913 Webster]

   Sleeping car, a railway car or carrriage, arranged with
      apartments and berths for sleeping.

   Sleeping partner (Com.), a dormant partner. See under
      Dormant.

   Sleeping table (Mining), a stationary inclined platform on
      which pulverized ore is washed; a kind of buddle.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dormancy \Dor"man*cy\, n. [From Dormant.]
   The state of being dormant; quiescence; abeyance.
   [1913 Webster]

         It is by lying dormant a long time, or being . . . very
         rarely exercised, that arbitrary power steals upon a
         people.                                  --Burke.
   [1913 Webster]

   2. (Her.) In a sleeping posture; as, a lion dormant; --
      distinguished from couchant.
      [1913 Webster]

   Dormant partner (Com.), a partner who takes no share in the
      active business of a company or partnership, but is
      entitled to a share of the profits, and subject to a share
      in losses; -- called also sleeping partner or silent
      partner.

   Dormant window (Arch.), a dormer window. See Dormer.

   Table dormant, a stationary table. [Obs.] --Chaucer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sleeping partner
    n 1: a partner (who usually provides capital) whose association
         with the enterprise is not public knowledge [syn: silent
         partner, sleeping partner]