Source : Webster's Revised Unabridged Dictionary (1913)

Orifice \Or"i*fice\, n. [F., from L. orificium; os, oris, a
   mouth + facere to make. See {Oral}, and {Fact}.]
   A mouth or aperture, as of a tube, pipe, etc.; an opening;
   as, the orifice of an artery or vein; the orifice of a wound.
   --Shak.

         Etna was bored through the top with a monstrous
         orifice.                                 --Addison.

Source : WordNet®

orifice
     n : an aperture or hole opening into a bodily cavity; "the
         orifice into the aorta from the lower left chamber of the
         heart" [syn: {opening}, {porta}]