The term "flying boat" simply refers to a seaplane that has a hull it uses for buoyancy, versus "float planes" that use fuselage mounted floats for buoyancy.
Well said, flyboy, crisp and clear. No confusion about that.
For anybody interested in "The Flying Boat" here's a nice little overview, with special attention to the gigantic Saunders-Roe Princess that added another 17 feet to the lenght of the Do-X and a whopping 63 feet to the Do-X wingspan. Alas it turned out to be a plane designed for a future that never existed...:
https://youtu.be/-f906Sy79hA?si=voTNDG1COL_8B29y
That's a wonderful shot, Donald