Sets aside Tom's battle scars? (8)
I believe the answer is:
earmarks
'sets aside' is the definition.
('earmark' can be a synonym of 'set aside')
'tom's battle scars?' is the wordplay.
'tom's battle' becomes 'ear' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'scars?' becomes 'marks' ('mark' can be a synonym of 'scar').
'ear'+'marks'='EARMARKS'
Can you help me to learn more?
(Other definitions for earmarks that I've seen before include "Characteristic features" , "Sets aside for particular purpose in aural way" , "Allocates; reserves" , "Designates for a particular purpose" , "Identifies" .)