What does aneroid mean?
The definition of aneroid
An”e*roid, a.
Etym: [Gr. -oid: cf. F. anéroïde.]

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.

An”e*roid, n.
An aneroid barometer.