Source : Webster's Revised Unabridged Dictionary (1913)

Obturate \Ob"tu*rate\, v. t. [imp. & p. p. {Obturated}; p. pr. &
   vb. n. {Obturating}.] [L. obturatus; p.p. of obturare.]
   To stop or close, as an opening; specif., (Ordnance), to stop
   (a gun breech) so as to prevent the escape of gas in firing.