Defn: An instrument for ascertaining the weight or density of air and gases.

AEROMETRIC
A`ër*o*met"ric, a.

Defn: Of or pertaining to aërometry; as, aërometric investigations.

AEROMETRY
A`ër*om"e*try, n. Etym: [Aëro- + -metry: cf. F. érométrie.]

Defn: The science of measuring the air, including the doctrine of its pressure, elasticity, rarefaction, and condensation; pneumatics.

AERONAT
A"ër*o*nat`, n. [F. aéronat. See Aëro-; Natation.]

Defn: A dirigible balloon.

AERONAUT
A"ër*o*naut, n. Etym: [F. aéronaute, fr. Gr. Nautical.]

Defn: An aërial navigator; a balloonist.

AERONAUTIC; AERONAUTICAL
A`ër*o*naut"ic, A`ër*o*naut"ic*al, a. Etym: [Cf. F. aéronauitique.]