1. An instrument for measuring atmospheric pressure that operates without liquid: An aneroid is a device that automatically records changes in air pressure with the movement of a pressure-sensitive element without the use of any fluids.
2. Etymology: from Greek a, "without" + neron, "water" + oid, "like".

"The word neron is derived from the Late Greek phrase neron hydor, "fresh water".

Relating to or referring to being without fluid or actuated without a flowing substance: The aneroid barometer measures air pressure by the action of air and not by using liquids.