Ăn'e-roid, a.

[Gr. ἀ priv., ὑγρός, wet, moist, and εἶδος, form.] Dispensing with the use of quicksilver, as a certain kind of 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.