air gauge

noun

variants or less commonly air gage

1

: a gauge for measuring air pressure

2

: a comparator in which the rate of escape of air between the surface under test (as that of a gun bore) and one of known curvature nearly fitting it (as that of a spindle inserted in the bore) is used as a measure of the difference between the two

Word History

First Known Use

1781, in the meaning defined at sense 1

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!