A gauge, as indicated by its numerous definitions, can mean a lot of things to different users. In order to determine its precise meaning, you would first have to look at the context in which this word is being used.

Generally, gauge is the term used to denote a typical form of measurement referring to an object's quantity, capacity or even its dimension. It may also refer to the instrument employed whenever an item is being measured or examined. Gauge may be the basis for making an evaluation or estimation like a test. In mathematics, gauge, as a concept, is applied when studying convex sets. In knitting, gauge would mean the fineness of the total stitches made within a certain length of the material. In physics, it is part of the group forming the mathematical mappings known as the gauge transformation. In sailing or water transportation, nautical gauge means the distance of a boat relative to another vessel including the wind factor. In land transportation specifically in railroads, gauge refers to the length between any two rails.

Gauge often refers to the measure of the thickness or the diameter of an object. Under the American wire gauge standard, gauge relates to the magnitude across the circle of the wire, or simply its diameter. As a medical term, gauge means the needle's diameter with respect to the Stubs Iron Wire Gauge. In the science of metallurgy, it pertains to the body comprising a metal sheet.

In engineering, gauges pertain to various devices that are utilized for measurement purposes. The list of types of gauge devices include the pressure gauge, the temperature gauge, the wire gauge, the bore gauge, the feeler gauge, the radius gauge, the thread pitch gauge, the strain gauge, the Vernier height gauge and the gauge blocks, among others.