Aeroplane prank: stewardess ultimately vanishing (3)
I believe the answer is:
jet
'aeroplane' is the definition.
(jet is a kind of aeroplane)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for jet that I've seen before include "Black; spurt" , "Glossy black colour" , "Rapid stream of liquid or gas" , "Jumbo plane?" , "Very black or fast plane" .)