Crown wants everyone to turn over last of the bones (8)
I believe the answer is:
patellae
'bones' is the definition.
(patella is a kind of bone)
'crown wants everyone to turn over last of the' is the wordplay.
'crown' becomes 'pate' (both can mean a person's head).
'wants' says to put letters next to each other.
'everyone' becomes 'all' (all people).
'to turn over' says the letters should be written backwards.
'last of' suggests the final letters.
The final letter of 'the' is 'e'.
'all' written backwards gives 'lla'.
'pate'+'lla'+'e'='PATELLAE'
(Other definitions for patellae that I've seen before include "Bones" , "The formal kneecaps" , "Bony bits" , "Late leap twisted kneecaps" .)