A little bit of code left behind (6)
I believe the answer is:
morsel
'a little bit' is the definition.
(I've seen this in another clue)
'code left behind' is the wordplay.
'code' becomes 'Morse' (Morse code).
'left' becomes 'l' (common abbreviation).
'behind' is a charade indicator (letters next to each other).
'morse'+'l'='MORSEL'
'of' is the link.
(Other definitions for morsel that I've seen before include "A tiny bit" , "Just a fragment of food" , "Bite to eat" , "Crumb" , "Tidbit" .)