Farm animal eats hot food (4)
I believe the answer is:
chow
'food' is the definition.
(chow is a kind of food)
'farm animal eats hot' is the wordplay.
'farm animal' becomes 'cow' (I've seen this before**).
'eats' is an insertion indicator.
'hot' becomes 'h'.
'cow' placed around 'h' is 'CHOW'.
(Other definitions for chow that I've seen before include "Barker" , "Grub" , "eats" , "Long-haired Chinese dog or slangy food" , "Mixed < dog" .)