Baker's dozens (4)
I believe the answer is:
eggs
'baker's dozens' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eggs that I've seen before include "Those scrambled, boiled, poached or fried" , "Breakfast items" , "Reproductive parts" , "Don't teach your grandmother to suck --" , "Reproductive cells" .)