Rich Liberal leaves apartment (3)
I believe the answer is:
fat
'rich' is the definition.
(rich can describe fat or creamy food)
'liberal leaves apartment' is the wordplay.
'liberal' becomes 'l' (abbreviation).
'leaves' 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 "Greasy substance" , "Corpulent; little (chance)" , "Naturally oily substance" , "Obese, having spare tyre etc" , "and 24: Overpaid City type" .)