Reprimand firmly (8)
I believe the answer is:
admonish
'reprimand firmly' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for admonish that I've seen before include "Forewarn" , "Chide, reprove" , "Warn sternly" , "criticise" , "Scold, wag the finger at" .)