A backward fool keeping himself to himself (5)
I believe the answer is:
aloof
'a backward' is the definition.
(thesaurus)
'fool keeping himself to himself' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'fool' is 'loof' which is present in the answer.
A single letter 'a' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for aloof that I've seen before include "Unapproachable, distant" , "Withdrawn, supercilious" , "Showing detached attitude" , "rather cold" , "Haughty and distant like a fool" .)