Edible, you can have it in cakes (4)
I believe the answer is:
fish
'edible' is the definition.
The definition and answer can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for fish that I've seen before include "Aquatic animal" , "Angle, troll" , "Aquarium" , "Eg, sturgeon" , "Possibly the sole" .)