Often written bush; see BUSH sb.2 [prob. f. BOUCHE v. to plug.] A metal plug that is drilled to form the vent or touch-hole of a cannon.
1862. F. Griffiths, Artil. Man. (ed. 9), 186. Bouches, vents.
1867. Smyth, Sailor’s Word-bk., Bush, or Bouche … the plug screwed into the metal of the gun at the place of the vent, which is then drilled in it.
