Eggs, perhaps, that don't stay intact long (9)
I believe the answer is:
breakfast
'eggs perhaps that don't stay intact long' is the definition.
The definition and answer can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
This is the entire clue.
Can you help me to learn more?
(Other definitions for breakfast that I've seen before include "First meal at Tiffany's" , "Eat in the morning" , "Fat bakers having a meal" , "Early meal" , "food" .)