amagi_(akagi-class_aircraft_carrier)
Planned first carrier (conversion from battlecruiser) of the Amagi class carrier, cancelled when the ship was wrecked on the stocks by the Great Tokyo Earthquake of 1923.
This deliberately-incorrect qualifier -- (akagi-class_aircraft_carrier) -- was formerly used in the Japanese Wikipedia article to distinguish it from the second Amagi (Unryuu-class aircraft carrier).