Painful method usually employed to break off toenail (9)
I believe the answer is:
emotional
'painful' is the definition.
'method usually employed to break off toenail' is the wordplay.
'method usually employed' becomes 'mo' (abbreviation for modus operandi).
'to break' indicates putting letters inside.
'off' indicates anagramming the letters.
'toenail' anagrammed gives 'etional'.
'mo' going within 'etional' is 'EMOTIONAL'.
(Other definitions for emotional that I've seen before include "Exhibiting strong feelings" , "Loving" , "tear-jerking" , "Arousing strong feeling" , "Deeply feeling" .)