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 This is inserted into the orifice and then withdrawn allowing easy viewing of the cavity being examined.
2. a prosthetic device serving to close an opening in the body. Can be used as a maxillofacial prosthesis to close a cleft palate.
3. A naming convention used to describe an anatomical structures that obturates an anatomical foramen or aperture