One prone to beat male involved in sick murder (7)
I believe the answer is:
drummer
'one prone to beat' is the definition.
I can't tell whether this definition defines the answer.
'male involved in sick murder' is the wordplay.
'male' becomes 'm' (common abbreviation).
'involved in' is an insertion indicator.
'sick' indicates an anagram.
'murder' anagrammed gives 'drumer'.
'm' going into 'drumer' is 'DRUMMER'.
Can you help me to learn more?
(Other definitions for drummer that I've seen before include "Group member" , "Someone who keeps 18 [RHYTHM]" , "Type of percussionist" , "salesman to America" , "Musician" .)