"Everything" bagel morsel (4)
I believe the answer is:
seed
'everything bagel morsel' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for seed that I've seen before include "one with potential to grow up?" , "High-ranked player in a knock-out tournament" , "Basis for new plant" , "Kernel" , "Pip; origin, beginning" .)