flying boat

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A large seaplane that floats on its hull rather than on pontoons.

from the GNU version of the Collaborative International Dictionary of English.

• A compact form of hydro-aëroplane having one central body, or hull.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a large seaplane that floats with its fuselage in the water rather than on pontoons