The Collaborative International Dictionary of English v.0.48:

Ghost \Ghost\ (g[=o]st), n. [OE. gast, gost, soul, spirit, AS.
   g[=a]st breath, spirit, soul; akin to OS. g[=e]st spirit,
   soul, D. geest, G. geist, and prob. to E. gaze, ghastly.]
   [1913 Webster]
   1. The spirit; the soul of man. [Obs.]
      [1913 Webster]

            Then gives her grieved ghost thus to lament.
                                                  --Spenser.
      [1913 Webster]

   2. The disembodied soul; the soul or spirit of a deceased
      person; a spirit appearing after death; an apparition; a
      specter.
      [1913 Webster]

            The mighty ghosts of our great Harrys rose. --Shak.
      [1913 Webster]

            I thought that I had died in sleep,
            And was a blessed ghost.              --Coleridge.
      [1913 Webster]

   3. Any faint shadowy semblance; an unsubstantial image; a
      phantom; a glimmering; as, not a ghost of a chance; the
      ghost of an idea.
      [1913 Webster]

            Each separate dying ember wrought its ghost upon the
            floor.                                --Poe.
      [1913 Webster]

   4. A false image formed in a telescope by reflection from the
      surfaces of one or more lenses.
      [1913 Webster]

   Ghost moth (Zool.), a large European moth (Hepialus
      humuli); so called from the white color of the male, and
      the peculiar hovering flight; -- called also great
      swift.

   Holy Ghost, the Holy Spirit; the Paraclete; the Comforter;
      (Theol.) the third person in the Trinity.

   To give up the ghost or To yield up the ghost, to die; to
      expire.
      [1913 Webster]

            And he gave up the ghost full softly. --Chaucer.
      [1913 Webster]

            Jacob . . . yielded up the ghost, and was gathered
            unto his people.                      --Gen. xlix.
                                                  33.
      [1913 Webster]