Extra food called for to be made fast (4)
I believe the answer is:
moor
'fast' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'extra food called for to be' is the wordplay.
'extra food' becomes 'moo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'called for' indicates a 'sounds like' (homophone) clue.
'to be' becomes 'are' (I've seen this in another clue).
'are' is a homophone of 'r'.
'moo'+'r'='MOOR'
'made' acts as a link.
Can you help me to learn more?
(Other definitions for moor that I've seen before include "Heather-covered tract" , "Heathery upland" , "Large area of open, uncultivated land" , "North African - secure a boat - tract of land" , "Secure boat to fixed object" .)