Source : Webster's Revised Unabridged Dictionary (1913)

   2. A wedgelike piece of stone, wood metal, or other material,
      used for various purposes, as:
      (a) (Masonry) to support and steady a stone.
      (b) (Gun.) To support the breech of a cannon.
      (c) (Print.) To wedge or lock up a form within a chase.
      (d) (Naut.) To prevent casks from rolling.

   {Hollow quoin}. See under {Hollow}.

   {Quoin post} (Canals), the post of a lock gate which abuts
      against the wall.

Hollow \Hol"low\, a. [OE. holow, holgh, holf, AS. holh a hollow,
   hole. Cf. {Hole}.]
   1. Having an empty space or cavity, natural or artificial,
      within a solid substance; not solid; excavated in the
      interior; as, a hollow tree; a hollow sphere.

            Hollow with boards shalt thou make it. --Ex. xxvii.
                                                  8.

   2. Depressed; concave; gaunt; sunken.

            With hollow eye and wrinkled brow.    --Shak.

   3. Reverberated from a cavity, or resembling such a sound;
      deep; muffled; as, a hollow roar. --Dryden.

   4. Not sincere or faithful; false; deceitful; not sound; as,
      a hollow heart; a hollow friend. --Milton.

   {Hollow newel} (Arch.), an opening in the center of a winding
      staircase in place of a newel post, the stairs being
      supported by the wall; an open newel; also, the
      stringpiece or rail winding around the well of such a
      staircase.

   {Hollow quoin} (Engin.), a pier of stone or brick made behind
      the lock gates of a canal, and containing a hollow or
      recess to receive the ends of the gates.

   {Hollow root}. (Bot.) See {Moschatel}.

   {Hollow square}. See {Square}.

   {Hollow ware}, hollow vessels; -- a trade name for cast-iron
      kitchen utensils, earthenware, etc.

   Syn: Syn.- Concave; sunken; low; vacant; empty; void; false;
        faithless; deceitful; treacherous.