Cube by artist who can manage food (9)
I believe the answer is:
dietitian
'cube by artist who can manage food' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'cube by artist' is the wordplay.
'cube' becomes 'die' (die is a kind of cube).
'by' says to put letters next to each other.
'artist' becomes 'Titian' (16th-century painter).
'die'+'titian'='DIETITIAN'
Can you help me to learn more?
(Other definitions for dietitian that I've seen before include "one who regulates courses" , "Initiated for food expert" , "Medical adviser" , "Food specialist" , "Food guru" .)