Webster's Revised Unabridged Dictionary · 1913

Aerostat

Aerostat ({not transcribed}) , noun

[French aérostat, from Greek {not transcribed} air + {not transcribed} placed. See Statics.]

1.
(Aeronautics) A balloon, especially a passive balloon; a balloon without motive power. Contrasted with aerodyne.
2.
A balloonist; an aeronaut.