1.(Aëronautics) An aëroplane with a boatlike or other understructure that enables it to travel on, or to rise from the surface of, a body of water by its own motive power; - now usually referred to as a seaplane.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in classic literature ?
These boxes contain the various parts of a hydro-aeroplane. I purpose assembling this upon the strip of beach described in Bowen's manuscript--the beach where he found the dead body of the apelike man--provided there is sufficient space above high water; otherwise we shall have to assemble it on deck and lower it over the side.
There is no use discussing any plan other than the hydro-aeroplane. We'll find the beach and get busy."
Down the coast they steamed toward the beach where Billings had made his crossing in the hydro-aeroplane and just at dusk the lookout announced a light dead ahead.
In its June 1917 edition, Pacific Service Magazine reported: "The company builds the Fageol Car equipped with the famous Hall-Scott 125-horsepower military hydro-aeroplane engines.