Doctor since second cut getting violent (7)
I believe the answer is:
drastic
'violent' is the definition.
(I've seen this before)
'doctor since second' is the wordplay.
'doctor' becomes 'Dr' (abbreviation).
'since' becomes 'as' (I've seen this in other clues).
'second' becomes 'tic' (tic or tick can mean a short amount of time).
'dr'+'as'+'tic'='DRASTIC'
'cut getting' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for drastic that I've seen before include "Very severe or serious" , "Extremely severe" , "Severe, radical (measures)" , "Grave" , "'Dramatic, extreme (7)'" .)