1) Ammunition 
In the field of firearms and airguns, obturation denotes necessary barrel blockage or fitment by a deformed soft projectile (obturation in general is closing up an opening). A bullet or pellet, made of soft material and often with a concave base, will flare under the heat and pressure of firing, filling the bore and engaging the barrel`s rifling.....
• (n.) The act of stopping up, or closing, an opening.
Obstruction or occlusion. ... Origin: see obturator ... Intermittent self-obturation, passage of a blunt object in a lumen or meatus to occlude it or to dilate it. ... (05 Mar 2000) ... 
(ob″tә-ra´shәn) obstruction. canal obturation filling of a root canal completely and densely with a nonirritating hermetic sealing agent.
Ob`tu·ra'tion noun [ Latin obturare to stop up: confer French obturation .] The act of stopping up, or closing, an opening. 'Deaf by an outward obturation .' Bp. Hall. 
Type: Term Pronunciation: ob′tū-rā′shŭn Definitions: 1. Obstruction or occlusion.