Reprimand; plant (6)
I believe the answer is:
rocket
This clue is a double definition.
'reprimand' is the first definition.
(I've seen this before)
'plant' is the second definition.
(rocket is a kind of plant)
(Other definitions for rocket that I've seen before include "Salad plant - shoot up" , "Go up very quickly" , "Firework and lettuce" , "Salad plant; missile" , "High speed steam engine (1829)" .)