cage components (4)
I believe the answer is:
ribs
'cage components' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ribs that I've seen before include "Curved bones around the chest" , "Arched bones in the upper body" , "Makes fun of - bones" , "Bones in chest, may be floating" , "Pairs of curved bones" .)