Which measurement is typically NOT associated with the term gauge?

The term "gauge" is primarily used in firearms and ammunition contexts, especially when referring to shotguns. The correct association of gauge typically relates to dimensions and characteristics specific to firearms, such as barrel width and shotgun size.

Barrel width refers to the diameter of the shotgun's barrel, which directly correlates to its gauge size. Shell thickness may also be relevant, as it can affect how ammunition fits and performs within the barrel. Shotgun size is fundamentally defined by its gauge, which determines the size of the shot and the type of shells that can be used.

Material density, on the other hand, does not typically fall under the definition of "gauge." While material density can impact the weight and performance of various objects, it is not a measurement associated with the sizing terminology of gauging in firearms. Thus, identifying material density as not being related to gauge is accurate in this context.