Food is hot but not the whole course (4)
I believe the answer is:
dish
'course' is the definition.
(I've seen this in other clues)
'food is hot but not the whole' is the wordplay.
'but not the whole' says the answer is hidden in the clue (only some letters are required).
'DISH' is hidden within 'food is hot'.
(Other definitions for dish that I've seen before include "something in the oven?" , "Bowl-shaped aerial; utterly destroy (colloq.)" , "someone very attractive" , "Lovely" , "Scotch" .)