A medic's engaged in final attack (7)
I believe the answer is:
lambast
'attack' is the definition.
'a medic's engaged in final' is the wordplay.
'medic' becomes 'MB' (Bachelor of Medicine).
'engaged in' is an insertion indicator.
'final' becomes 'last' (synonyms).
'a'+'mb'='amb'
'amb' going within 'last' is 'LAMBAST'.
(Other definitions for lambast that I've seen before include "Reprimand" , "Berate" , "Thrash" , "Roast" , "Bash" .)