Rich Liberal leaving apartment (3)
I believe the answer is:
fat
'rich' is the definition.
(rich can describe fat or creamy food)
'liberal leaving apartment' is the wordplay.
'liberal' becomes 'l' (abbreviation).
'leaving' indicates named letters should be taken away.
'apartment' becomes 'flat' (synonyms).
'flat' with 'l' removed is 'FAT'.
(Other definitions for fat that I've seen before include "Substantial" , "Portly" , "Obese, overweight" , "Excess body weight" , "Profitable" .)