The Collaborative International Dictionary of English v.0.48:

Obturator \Ob"tu*ra`tor\, n. [NL., fr. L. obturare to stop up:
   cf. F. obturateur.]
   1. That which closes or stops an opening.
      [1913 Webster]

   2. (Surg.) An apparatus designed to close an unnatural
      opening, as a fissure of the palate.
      [1913 Webster]

   3. (Ordnance) Any device for preventing the escape of gas
      through the breech mechanism of a breech-loading gun; a
      gas check.
      [Webster 1913 Suppl.]

   4. (Photog.) A camera shutter.
      [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Obturator \Ob"tu*ra`tor\, a. (Anat.)
   Serving as an obturator; closing an opening; pertaining to,
   or in the region of, the obturator foramen; as, the obturator
   nerve.
   [1913 Webster]

   Obturator foramen (Anat.), an opening situated between the
      public and ischial parts of the innominate bone and closed
      by the obturator membrane; the thyroid foramen.
      [1913 Webster]

WordNet (r) 3.0 (2006):

obturator
    n 1: a prosthesis used to close an opening (as to close an
         opening of the hard palate in cases of cleft palate)