Admonishment (8)
(Another definition for rebuking that I've seen is " Scolding".)
'admonishment' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for caution that I've seen before include "Hoot" , "amusing type" , "Official warning" , "Caveat, prudence" , "Vigilance" .)