noun

• (surgery) An object used to obstruct a hole, such as a fissure of the palate.
• (anatomy) The membrane vessels, etc. that close the obturator foramen, or thyroid foramen, a large opening or fenestra in the anterior part of the hip bone.
• (engineering) A valve closure member (disk, gate, plug, etc.).
• (ordnance) Any device for preventing the escape of gas through the breech mechanism of a breech-loading gun; a gas check.
• (photography) A camera shutter.