Source : Webster's Revised Unabridged Dictionary (1913)

Ceiling \Ceil"ing\, n. [See {Cell}, v. t.]
   1. (Arch.)
      (a) The inside lining of a room overhead; the under side
          of the floor above; the upper surface opposite to the
          floor.
      (b) The lining or finishing of any wall or other surface,
          with plaster, thin boards, etc.; also, the work when
          done.

   2. (Naut.) The inner planking of a vessel.

   {Camp ceiling}. See under {Camp}.

   {Ceiling boards}, Thin narrow boards used to ceil with.

Ceil \Ceil\ (s[=e]l), v. t. [imp. & p. p. {Ceiled} (s[=e]ld); p.
   pr. & vb. n. {Ceiling}.] [From an older noun, fr. F. ciel
   heaven, canopy, fr. L. caelum heaven, vault, arch, covering;
   cf. Gr. koi^los hollow.]
   1. To overlay or cover the inner side of the roof of; to
      furnish with a ceiling; as, to ceil a room.

            The greater house he ceiled with fir tree. --2
                                                  Chron. iii. 5

   2. To line or finish a surface, as of a wall, with plaster,
      stucco, thin boards, or the like.

Source : WordNet®

ceiling
     n 1: the overhead upper surface of a room; "he hated painting the
          ceiling"
     2: (meteorology) altitude of the lowest layer of clouds
     3: an upper limit on what is allowed; "they established a cap
        for prices" [syn: {cap}]
     4: maximum altitude at which a plane can fly (under specified
        conditions)