Spaceship (6)
'spaceship' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for rocket that I've seen before include "Aerial projectile" , "Salad plant; missile" , "Severe criticism" , "go fast" , "One's fired up" .)
'spaceship' is the definition.
(I have seen 'Potential spaceship ' mean 'ufo' so perhaps 'spaceship' could also mean 'ufo')
This is all the clue.
(Other definitions for ufo that I've seen before include "ET transporter?" , "Potential alien craft" , "ET ship" , "Initially and formally, flying saucer" , "(Possibly) alien craft" .)