diameter
straight line segment that passes through the center of a circle
bore
measurement of diameter of a cylinder through which a piston travels
beam diameter
width of an electromagnetic beam
equivalent spherical diameter
diameter of a sphere of the same volume as an irregularly-shaped subject
calibre
internal diameter of the barrel of a gun
hydraulic diameter
measure of a channel flow efficiency
diameter of moon
diameter
critical diameter
minimal diameter of a cylindrical exposive charge for propagation of a stable detonation
Sauter mean diameter
average of particle size
Nominal Pipe Size
North American set of standard sizes for pipes