Severe reprimand (6)
I believe the answer is:
rocket
'severe reprimand' is the definition.
(as in 'getting a rocket' from a someone)
This is all the clue.
(Other definitions for rocket that I've seen before include "Projectile, missile" , "Element in firework display" , "Soar" , "Structure that flies by expelling gases - or a reprimand" , "Go up suddenly" .)