obturate

from WordNet (r) 3.0 (2006)

obturate
    v 1: block passage through; "obstruct the path" [syn:
         {obstruct}, {obturate}, {impede}, {occlude}, {jam},
         {block}, {close up}] [ant: {disengage}, {free}]

from The Collaborative International Dictionary of English v.0.48

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.
   [Webster 1913 Suppl.]