White Elephant or maybe, Dodo (a bit unfair to Elephants & Dodos though !)
final thought; how about Brabazon III ?
Before I get shot down I checked, there was already a Brab' II :-
Mark II
In 1946 it was decided to make the second prototype based on the Bristol Coupled Proteus turboprop engines - eight paired turboprops driving 4-bladed screws through a common gearbox..[2] This would increase cruising speed from 260 to 330 mph (420–530 km/h) and ceiling while reducing the empty weight by about 10,000 lb (4,540 kg). This Brabazon Mark II, would be able to cross the Atlantic (London-New York) in a reduced time of 12 hours.
Although the Proteus was slimmer than the Centaurus, the wing thickness was not to be reduced in the Mark II but the leading edge would be extended around the engines.
Changes to the wheel arrangement planned for the Mark II would have allowed it to use most runways on both the North Atlantic and Empire routes.