Herb carried on misbehaving (9)
I believe the answer is:
coriander
'herb' is the definition.
(coriander is a kind of herb)
'carried on misbehaving' is the wordplay.
'misbehaving' indicates an anagram.
'carried'+'on'='carriedon'
'carriedon' anagrammed gives 'CORIANDER'.
(Other definitions for coriander that I've seen before include "ingredient of coronation chicken?" , "Aromatic herb" , "Carried on with the strange herb" , "Herb used with carrot for soup" , "Plant with spicy fruit" .)