Aneroid

Part of speech: noun (n.)

An aneroid barometer.

Part of speech: adjective (a.)

Containing no liquid; -- said of kind of barometer. Aneroid barometer, a barometer the action of which depends on the varying pressure of the atmosphere upon the elastic top of a metallic box (shaped like a watch) from which the air has been exhausted. An index shows the variation of pressure.