Seaman, getting posted, didn't like being miles away (6-6)
I believe the answer is:
absent-minded
'being miles away' is the definition.
I can't judge whether this defines the answer.
'seaman getting posted didn't' is the wordplay.
'seaman' becomes 'ab' (short for able seaman).
'getting' is a charade indicator (letters next to each other).
'posted' becomes 'sent' ('send' can be a synonym of 'post').
'didn't' becomes 'minded' (I can't justify this - if you can you should believe this answer much more).
'ab'+'sent'+'minded'='ABSENT-MINDED'
'like' is the link.
Can you help me to learn more?
(Other definitions for absent-minded that I've seen before include "Scatty" , "Prone to forgetfulness" , "Vague and forgetful" , "Wandering" , "Given to woolgathering" .)