Supplied a loud fellow with food (3)
I believe the answer is:
fed
'supplied' is the definition.
(feeding is a kind of supplying)
'a loud fellow with food' is the wordplay.
I cannot really understand how this works, but
'loud' could be 'f' (short for forte - 'loud' in music) and 'f' is found in the answer.
'fellow' could be 'ed' (short for Edward) and 'ed' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for fed that I've seen before include "Gave food to (someone)" , "Dished up food" , "Banking authority" , "Nourished" , "American cop" .)