Act out of character, disturbed to see one with a target (6)
I believe the answer is:
archer
'one with a target' is the definition.
(an archer fires arrows at a target)
'act out of character disturbed' is the wordplay.
'out of' is a deletion indicator.
'disturbed' is an anagram indicator.
'character' with 'act' taken away is 'charer'.
'charer' is an anagram of 'ARCHER'.
'to see' acts as a link.
(Other definitions for archer that I've seen before include "His sport is the bow and arrow" , "A bow-and-arrow man" , "sign" , "A 19 lord - old soldier" , "was more roguish" .)