Some chest bones (4)
I believe the answer is:
ribs
'some chest bones' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ribs that I've seen before include "Arched bones in the upper body" , "Spurs?" , "Arched bones extending from the spine" , "cage" , "Chest bones, tasty when spare" .)