Wiktionary
n. (context lang=en aviation obsolete) a floatplane, an airplane specialized for operating on water, having pontoon floats instead of skids or wheels
Usage examples of "hydroaeroplane".
The hydroaeroplane feathered along the water, throwing a cloud of white spray, then slowly rose in the air.
That was when he saw the hydroaeroplane with Burnside and myself carrying the wireless torpedo.
This hydroaeroplane yeggman is after something besides jewels to-night.
I fancied I could almost hear the ripping and tearing of the tough rubber-coated silken wings of the hydroaeroplane as the wind widened the perforation the gun had made.
We might ride in hydroaeroplanes, delve into the very soul by psychanalysis, perhaps even run our machines by the internal forces of radium—even marry according to Galton or Mendel.
It was the mention of the hydroaeroplane which precipitated the first outspoken skepticism, and then Ajor came to my defense.