Source : Webster's Revised Unabridged Dictionary (1913)

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

            Then gives her grieved ghost thus to lament.
                                                  --Spenser.

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

            The mighty ghosts of our great Harrys rose. --Shak.

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

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

            Each separate dying ember wrought its ghost upon the
            floor.                                --Poe.

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

   {Ghost moth} (Zo["o]l.), 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 or yield up} {the ghost}, to die; to expire.

            And he gave up the ghost full softly. --Chaucer.

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

Holy \Ho"ly\, a. [Compar. {Holier}; superl. {Holiest}.] [OE.
   holi, hali, AS. h[=a]lig, fr. h[ae]l health, salvation,
   happiness, fr. h[=a]l whole, well; akin to OS. h?lag, D. & G.
   heilig, OHG. heilac, Dan. hellig, Sw. helig, Icel. heilagr.
   See {Whole}, and cf. {Halibut}, {Halidom}, {Hallow},
   {Hollyhock}.]
   1. Set apart to the service or worship of God; hallowed;
      sacred; reserved from profane or common use; holy vessels;
      a holy priesthood. ``Holy rites and solemn feasts.''
      --Milton.

   2. Spiritually whole or sound; of unimpaired innocence and
      virtue; free from sinful affections; pure in heart; godly;
      pious; irreproachable; guiltless; acceptable to God.

            Now through her round of holy thought The Church our
            annual steps has brought.             --Keble.

   {Holy Alliance} (Hist.), a league ostensibly for conserving
      religion, justice, and peace in Europe, but really for
      repressing popular tendencies toward constitutional
      government, entered into by Alexander I. of Russia,
      Francis I. of Austria, and Frederic William III. of
      Prussia, at Paris, on the 26th of September, 1815, and
      subsequently joined by all the sovereigns of Europe,
      except the pope and the king of England.

   {Holy bark}. See {Cascara sagrada}.

   {Holy Communion}. See {Eucharist}.

   {Holy family} (Art), a picture in which the infant Christ,
      his parents, and others of his family are represented.

   {Holy Father}, a title of the pope.

   {Holy Ghost} (Theol.),the third person of the Trinity; the
      Comforter; the Paraclete.

   {Holy Grail}. See {Grail}.

   {Holy grass} (Bot.), a sweet-scented grass ({Hierochloa
      borealis} and {H. alpina}). In the north of Europe it was
      formerly strewed before church doors on saints' days;
      whence the name. It is common in the northern and western
      parts of the United States. Called also {vanilla, or
      Seneca, grass}.

   {Holy Innocents' day}, Childermas day.

   {Holy Land}, Palestine, the birthplace of Christianity.

   {Holy office}, the Inquisition.

   {Holy of holies} (Script.), the innermost apartment of the
      Jewish tabernacle or temple, where the ark was kept, and
      where no person entered, except the high priest once a
      year.

   {Holy One}.
      (a) The Supreme Being; -- so called by way of emphasis. ``
          The Holy One of Israel.'' --Is. xliii. 14.
      (b) One separated to the service of God.

   {Holy orders}. See {Order}.

   {Holy rood}, the cross or crucifix, particularly one placed,
      in churches. over the entrance to the chancel.

   {Holy rope}, a plant, the hemp agrimony.

   {Holy Saturday} (Eccl.), the Saturday immediately preceding
      the festival of Easter; the vigil of Easter.

   {Holy Spirit}, same as {Holy Ghost} (above).

   {Holy Spirit plant}. See {Dove plant}.

   {Holy thistle} (Bot.), the blessed thistle. See under
      {Thistle}.

   {Holy Thursday}. (Eccl.)
      (a) (Episcopal Ch.) Ascension day.
      (b) (R. C. Ch.) The Thursday in Holy Week; Maundy
          Thursday.

   {Holy war}, a crusade; an expedition carried on by Christians
      against the Saracens in the Holy Land, in the eleventh,
      twelfth, and thirteenth centuries, for the possession of
      the holy places.

Source : WordNet®

Holy Ghost
     n : the third person in the Trinity; Jesus promised the Apostles
         that he would send the Holy Spirit after his Crucifixion
         and Resurrection; it came on Pentecost [syn: {Holy Spirit}]