Brute force said to break good man (6)
I believe the answer is:
sadist
'brute' is the definition.
'force said to break good man' is the wordplay.
'force' is an anagram indicator (letters must be forced into a new order).
'to break' means one lot of letters goes inside another.
'good man' becomes 'st' ().
'said' anagrammed gives 'adis'.
'adis' placed into 'st' is 'SADIST'.
(Other definitions for sadist that I've seen before include "One who enjoys being cruel" , "One gaining pleasure from inflicting pain on another" , "It's sad to find person who enjoys hurting others" , "Cruel person, takes pleasure in it" , "An amalgam, made up of two or more parts" .)