Deserve each service (4)
I believe the answer is:
earn
'deserve' is the definition.
(I've seen this in another clue)
'each service' is the wordplay.
'each' becomes 'ea'.
'service' becomes 'RN' (abbreviation for Royal Navy).
'ea'+'rn'='EARN'
(Other definitions for earn that I've seen before include "Obtain (money) in return for labour or services" , "Gain (money, reputation, etc)" , "Merit (a reward)" , "Receive in return for" , "Twist out of shape" .)