Merriam-Webster's Collegiate® Dictionary, 11th Edition
GAUGE
I. noun also gage
Etymology: Middle English gauge, from Anglo-French
Date: 15th century
1. a measurement (as of linear dimension) according to some standard or system: as, the distance between the rails of a railroad, the size of a shotgun barrel's inner diameter nominally expressed as the number of lead balls each just fitting that diameter required to make a pound , the thickness of a thin material (as sheet metal or plastic film), the diameter of a slender object (as wire or a hypodermic needle), the fineness of a knitted fabric expressed by the number of loops per unit width, dimensions, size , measure 1 , an instrument for or a means of measuring or testing: as, an instrument for measuring a dimension or for testing mechanical accuracy, an instrument with a graduated scale or dial for measuring or indicating quantity, relative position of a ship with reference to another ship and the wind, a function introduced into a field equation to produce a convenient form of the equation but having no observable physical consequences, see: standard
II. transitive verb also gage (gauged; also gaged; gauging; also gaging)
Date: 15th century
1. to measure precisely the size, dimensions, or other measurable quantity of, to determine the capacity or contents of, estimate , judge ,
2. to check for conformity to specifications or limits, to measure off or set out