Bird embodied by headless god for all time (8)
I believe the answer is:
eternity
'all time' is the definition.
'bird embodied by headless god' is the wordplay.
'bird' becomes 'ern' (ern is a kind of bird).
'embodied' becomes 'ity' (I can't justify this - if you can you should give a lot more credence to this answer).
'by' is a charade indicator (letters next to each other).
'headless' means to remove the first letter.
'god' becomes 'set' (Egyptian god).
'set' with its first letter taken away is 'et'.
'ern'+'ity'='ernity'
'ernity' after 'et' is 'ETERNITY'.
'for' is the link.
Can you help me to learn more?
(Other definitions for eternity that I've seen before include "destination of film?" , "That's a very long time" , "Type of ring" , "Entirety (anag.)" , "Forever and ever" .)