from
The Collaborative International Dictionary of English v.0.48
Dispart \Dis*part"\, n.
1. (Gun.) The difference between the thickness of the metal
at the mouth and at the breech of a piece of ordnance.
[1913 Webster]
On account of the dispart, the line of aim or line
of metal, which is in a plane passing through the
axis of the gun, always makes a small angle with the
axis. --Eng. Cys.
[1913 Webster]
2. (Gun.) A piece of metal placed on the muzzle, or near the
trunnions, on the top of a piece of ordnance, to make the
line of sight parallel to the axis of the bore; -- called
also {dispart sight}, and {muzzle sight}.
[1913 Webster]