Rating bowler’s target (4)
I believe the answer is:
jack
I believe this clue is a double definition.
'rating' is the first definition.
(both can mean a sailor)
'bowler's target' is the second definition.
(in bowls, players bowl balls towards the jack)
(Other definitions for jack that I've seen before include "Card; man's name" , "Raising device, socket" , "Jill's other half?" , "Sailor; flag" , "Boy - lifting device" .)