obturator

n. someone or something that obturates, that which closes or obstructs

Obturator, is a term used to refer to an object used to obstruct a hole. Specifically, it can refer to: 1. The central removable core of a medical instrument (e.g. a proctoscope) which allows easy insertion of the tip into the anus or other orifice. The obturator typically has a rounded end which protrudes through the far opening of the instrument. This is inserted into the orifice and then withdrawn allowing easy viewing of the cavity being examined.Obturator ring
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Obturator /ob·tu·ra·tor/ a disk or plate, natural or artificial, that closes an opening. ob·tu·ra·tor n. 1. [more]Obturator - Community and Resources

Noun
1. a prosthesis used to close an opening (as to close an opening of the hard palate in cases of cleft palate)
(hypernym) prosthesis, prosthetic device
(derivation) obstruct, obturate, impede, occlude, jam, block, close up

(n.)
That which closes or stops an opening.
  

(n.)
An apparatus designed to close an unnatural opening, as a fissure of the palate.
  

(a.)
Serving as an obturator; closing an opening; pertaining to, or in the region of, the obturator foramen; as, the obturator nerve.