Reads list for new naval officer (5,3,4)
I believe the answer is:
first sea lord
'naval officer' is the definition.
'reads list for new' is the wordplay.
'new' indicates anagramming the letters.
'reads'+'list'+'for'='readslistfor'
'readslistfor' anagrammed gives 'FIRST SEA LORD'.
(Other definitions for first sea lord that I've seen before include "Head of the Royal Navy" , "He's responsible for naval ships" .)