Food not hot on cold plate (4)
I believe the answer is:
disc
'plate' is the definition.
(I know that disc is a type of flying disc)
'food not hot on cold' is the wordplay.
'food' becomes 'dish' (dish is a kind of food).
'not' suggests deleting specific letters.
'hot' becomes 'h' (abbreviation, eg on taps).
'on cold' becomes 'c' (eg on taps. I am not sure about the 'on' bit.).
'dish' with 'h' removed is 'dis'.
'dis'+'c'='DISC'
Can you help me to learn more?
(Other definitions for disc that I've seen before include "jockey may be after" , "Flat thin circular body" , "Protein-constituent acid" , "In Olympic event" , "Flat, circular plate - record" .)