Father holds bird to display bone (5)
I believe the answer is:
femur
'bone' is the definition.
(femur is a kind of bone)
'father holds bird' is the wordplay.
'father' becomes 'fr' (abbreviation as in a priest's title).
'holds' means one lot of letters goes inside another.
'bird' becomes 'emu' (emu is a type of bird).
'fr' placed around 'emu' is 'FEMUR'.
'to display' acts as a link.
(Other definitions for femur that I've seen before include "bit of leg" , "Thigh bone" , "Large bone" , "Part of leg" , "Bone in leg" .)