Hold forth, disturbing medical (7)
I believe the answer is:
declaim
'hold forth' is the definition.
(I've seen this before)
'disturbing medical' is the wordplay.
'disturbing' indicates anagramming the letters (I've seen this in other clues).
'medical' with letters rearranged gives 'DECLAIM'.
(Other definitions for declaim that I've seen before include "rant" , "Harangue" , "Utter rhetorically" , "Deliver an impassioned speech" , "Rail against" .)