The Collaborative International Dictionary of English v.0.48:

Aero \A"["e]r*o\, n.
   An a["e]roplane, airship, or the like. [Colloq. in 1900, now
   obsolescent.]
   [Webster 1913 Suppl. +PJC]

The Collaborative International Dictionary of English v.0.48:

Aero \Aer"*o\, adj.
   of or pertaining to aeronautics or aircraft.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Aero- \A"["e]r*o-\ [Gr. ?, ?, air.]
   The combining form of the Greek word meaning air.
   [1913 Webster]