An abreviation for the Executor
class Star Dreadnought (
Star Wars), commonly called a "super star destroyer".
A gigantic 17.6 km (11 mile) battleship, the first example, Executor, was
Darth Vader's flagship during the Empire Strikes Back.
The second SSD, Lusankya, was secretly buried under the surface of Coruscant, and later, under the control of a cloned Palpatine, burst up out of the planet and rose to space, killing some hundreds of millions in the process.