Separated from a quiet little fellow (5)
I believe the answer is:
apart
'separated from' is the definition.
(I've seen this in another clue)
'a quiet little fellow' is the wordplay.
'quiet' becomes 'pp' (musical abbreviation for pianissimo).
'little' means to remove the last letter (the word is not quite complete).
'fellow' becomes 'art' (I can't justify this - if you can you should believe this answer much more).
'pp' with its last letter removed is 'p'.
'a'+'p'+'art'='APART'
Can you help me to learn more?
(Other definitions for apart that I've seen before include "Independently" , "aloof" , "In pieces; separate" , "Estranged - in pieces" , "Separated physically" .)