gage / gauge are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
gage: NA
gauge: (noun) a measuring instrument for measuring and indicating a quantity such as the thickness of wire or the amount of rain etc.. (noun) accepted or approved instance or example of a quantity or quality against which others are judged or measured or compared. (noun) the distance between the rails of a railway or between the wheels of a train. (noun) the thickness of wire. (verb) rub to a uniform size. (verb) determine the capacity, volume, or contents of by measurement and calculation. (verb) measure precisely and against a standard. (verb) adapt to a specified measurement. (verb) mix in specific proportions.
gage: g·EY·jh
gauge: g·EY·jh
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)