Fed up like the proverbial calf (6)
I believe the answer is:
fatted
'like the proverbial calf' is the definition.
(I've seen this in another clue)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for fatted that I've seen before include "revealing such calves?" , "The calf for the Prodical Son" , "Teh calf for the Prodigal Son" , "The kind of calf for the Prodigal Son" , "Condition of calf for the Prodigal Son" .)